During Story Mode, Gohan and Krillin encounter the Ginyu Force, and Gohan is impressed by their poses. This makes Krillin believe Gohan was inspired by them to become the Great Saiyaman, a line of thought that was a very common fan theory.
For years, the various forms of Majin Buu were given different names to differentiate them, such as Good/Fat Buu for the first form of Buu, Evil Buu for the dark gray form, Super Buu for the variation that was created after Evil Buu ate Fat Buu, and Kid Buu for the "pure" form. At one point in the story mode, Goku referes to Kid Buu as exactly that.
I recently had a daughter and she is two years old. As I watch her grow up it reminds me of Gohan. Hes smart and strong, maybe not as strong in the recent episodes, but hes tough. My favorite [arc of the manga], because I love Gohan, is the Cell arc from Dragon Ball Z and when he started going to high school as the Great Saiyaman.
The Jump Festa trailer was set to the song "We Were Angels" by Hironobu Kageyama, the second ending theme of Dragon Ball Z from Episode 200 onwards. This brought a lot of emotions for fans who missed his music.
The launch trailer used for outside of Japan was in English and was purposefully made in a style that emulates the much beloved classic Toonami promos. Fans loved it.
The developers put in an incredible amount of work to make everyone's animations look like they were ripped straight out of the manga. Best shown off here.
They could've made Gotenks' intro animation the fusion into Super Saiyan 3. Instead, along with the Goten and Trunks models, ArcSys created models of Gotenks himself in his normal form, and as a Super Saiyan as well.
Dummied Out: Dataminers found quite a bit of hidden, extra things in the files of the PC version:
Fully rendered models of Goku and Vegeta during the Saiyan Saga. They became playable characters for the third DLC content pack.
Two unused plaza locations. One is a Saiyan space pod, and the other is a gold Mr. Satan statue. Both of these ended up being used for online events: The space pod for raid bosses, and the statue for faction battles.
Audio files have the announcer calling out for Cooler. Cooler was later announced for the fourth DLC content pack at EVO 2018.
Super Attacks and Meteor Attacks are generally referred to as "Level 1 (Supers)" and "Level 3 (Supers)" by fans.
Owing to being an ArcSys game, transformation Meteor Attacks are known as "Installs".
Goku and Vegeta in their Saiyan Saga forms included as DLC are often called "Base Goku/Vegeta" to differentiate them from Super Saiyan Goku/Vegeta, and Super Saiyan Blue Goku/Vegeta.
Android 16's self-destructing Meteor Attack —officially named "The Final Power that should never be used" ("Last Resort" in the English releases)—requires 16 to grab his opponent for it to work. If it lands, it takes out the opponent's character in one hit while taking 16 down to a pixel of health. No one should be surprised, then, that people have referred to this move as "The Hug of Death."
"Team My Two Dads" for the team of Gohan, Goku, and Piccolo, since Gohan's fighting alongside both his dad and his most prominent, non-blood-related father figure.
"Majin Bae", "Majin Thot", "Majin Boobs" or "Majin Rogue" for Android 21, specifically her playable form, for having Majin characteristics and being able to take the powers of her opponents. She's also commonly just called "Majin 21" or "Majin Android 21" for the same reasons, though she's never referred to as a Majin in the story.
Some of the alternate color palettes are rife for nickname potential like "Pillsbury Dough Buu"/"Stay Puft Marshmallow Buu" for Fat Buu's white color palette, or "Kool-Aid Buu" for his red color palette.
For a wider example, if an attack was the subject of a memorable joke in Dragon Ball Z Abridged, the community will often use that joke as the attack's name. For example, Base Goku's smash attack gets called "Goku Time" while Cooler's Fatal Combination is "(Planting a) Dumbass Tree".
God-Created Canon Foreigner: Akira Toriyama designed Android 21 specifically for this game. She's actually a reasonably important character to the backstory of Dr. Gero and Android 16, and could fit into the primary canon.
When the game's official Japanese website went live in August 2017, fans noticed that Teen Gohan and Fat Buu's profiles had the URLs "gohan-y" and "majinboo-z", respectively; this lead to speculation that alternate versions of the two characters would be present in the game, with Adult Gohan and Kid Buu being seen as the most likely candidates. Sure enough, both characters were confirmed the following November.
Due to them looking alike, a number of fans figured Android 21 was the mother of Gero's son, whom 16 was modeled after. We find out later on that she is in fact the mother of Gero's son, but she has forgotten Gero besides the fact that the thought of him makes her want to cry.
Both Broly and Bardock were predicted to be DLC, due to the popularity of both the characters and a leak stating that they would be among the first. They were the first two DLC characters announced for the game.
One of the predictions for FighterZ's second season of DLC would be that Jiren would be a new fighter. He was one of the very first characters confirmed for Season 2. The Super incarnation of Broly was also predicted, and ended up confirmed before the third and fourth DLC characters of the season.
Model Dissonance: Like Guilty Gear Xrd, FighterZ uses 3D models that try to emulate 2D sprites with added snazzy camera angles. As such, things may look weird if one pays close attention to the fact that the characters literally quarter-face towards each other during their idle stances and/or attacks instead of aiming them directly straight forward. Piccolo and Goku Black in their idle stances are some of the few who actually avert this.
Newbie Boom: The Dragon Ball franchise is well-known name worldwide. The hype and quality surrounding this game paid off and became Arc System Works' most successful fighting game in history. This has resulted in Discord servers, Twitch streams, Facebook groups and so on that were influential in bringing in many casual gamers who loved the Dragon Ball franchise and wanted to get better at the game. Some fans decided to take a look at ASW's older titles, most notably Guilty Gear Xrd, which inspired the creation of the game and also uses the Unreal Engine just like DBFZ. The success and prestige of the game also motivated quite a few gamers and fighting game fans to revisit the Dragon Ball franchise in general.
No Dub for You: The game didn't receive any other dub besides English dub.
Chris Ayres has been dealing with COPD throughout 2017 so Frieza's English voice is provided by Daman Mills, Ayres's understudy, who has also been providing voicework for Frieza in Dragon Ball Super in Ayres' absence.
The Other Marty: Vic Mignogna had already reprised his role as the original incarnation of Broly, as well as playing the Super incarnation in his debut film. It's likely that he was originally meant to return as the latter before the above accusations led him to being replaced.
Playing Against Type: Jeannie Tirado tends to play Nice Girls. Here, she's the English voice of Android 21 (who's classified as a villain, is one of the final remnants of the very evil Red Ribbon Army, and is the overall Big Bad of the game's story). Goes further in that 21 is actually a tortured soul who wants to be a Nice Girl but is possessed of psychological and biological impulses that make it impossible for her to lead a normal life.
While playing Hot-Blooded characters is nothing new for Johnny Yong Bosch, playing a massive musclehead and berserker like Broly who only screams is completely new.
Posthumous Credit: Hiromi Tsuru, Bulma's Japanese voice actress, passed away on November 16, 2017 at the age of 57 from aortic dissection. Thankfully, she recorded all of her lines for this game prior to her passing.
Relationship Voice Actor: Several members of the Japanese voice cast have been featured in other offerings by Arc System Works; from Guilty Gear alone you do currently have Norio Wakamoto (Cell/Johnny), Takeshi Kusao (Future Trunks & the Trunks half of Gotenks/Ky), Hikaru Midorikawa (Android 16 & Tenshinhan/Bedman) and Tetsu Inada (Nappa/Leo) together in another game (one that's even styled closer to Xrd nonetheless with the character comparisons in question).
Role Reprise: All of the characters retain their original Japanese voice actors (and counting those who have already darrin'd someone).
What Could Have Been: Chris Ayres wanted to reprise his role as Frieza for this game. Unfortunately, his COPD reached a critical, potentially terminal stage, which forced him to focus almost entirely on his health.