"Khura'in Jesus", for Pees'lubn Andistan'dhin. After he reveals his true nature, "Heavy Metal Jesus" became just as, if not more, popular for the same.
Some people nickname Nahyuta Sahdmadhi Elsa because of their similar hairstyles and Nahyuta's habit of saying "let it go". Both of them also keep their true feelings hidden in an attempt to protect their loved ones.
A lot of people predicted that Trucy was going to be a defendant, thanks to multiple screenshots showing a magic show while Trucy herself was conspicuously absent.
Many people guessed that Maya would return when trailers showed Phoenix traveling to a country called the "Kingdom of Kurain", though this was more wishful thinking than anything... until it was actually confirmed. Following this, quite a few people predicted that her propensity to get accused as a murderer would come back to haunt her even overseas and that ended up being the plot of "The Rite of Turnabout".
Many people guessed Apollo's deceased father was a musician.
Milestone Celebration: The game was released in 2016, the franchise's 15th anniversary. In a twist of fate, this is also true in-universe as well (Phoenix Wright: Ace Attorney is set in 2016, which is made relevant in-game by the DL-6 Incident, an event that happened in the year of the original game's Japanese GBA release).
Missing Trailer Scene: The launch trailer shows Ahlbi Ur'gaid with Psyche-Locks, which never happens in the final game. The scene in Case 5 where you find out he managed to sneak into the palace plays out as if one could have been there, so it's possible it was cut.
Just like the previous game, the 3DS version of the game has been released in the West only in English and digital format, when the series previously had localizations into other languages such as French, Spanish, German, Italian of similar quality to the English localization, as well as getting released on physical format. This also means that if the country does not have access to the Nintendo eShop, they will not be able to download the game. The iOS and Android ports that were released a year later averts this, which is as usual available anywhere where there is App Store and Google Play access, which is pretty much worldwide, but the 3DS version is still this as there is still a considerable amount of countries without eShop access.
The second set of DLC costumes based on Sengoku Basara characters has not been announced outside of Japan and is unlikely to be released anywhere else, since most of that series has not been released outside Japan itself.
The Other Darrin: In the Japanese version, Ema Skye is voiced by Marina Inoue instead of Satomi Hanamura, who had voiced her in the promo trailers of previous games. This is most likely due to Satomi also being the voice actor for Maya Fey in the trailers, and she is set to reprise that role; thus the game staff decided Ema and Maya should have different seiyuu now.
Polished Port: Again, the iOS and Android ports that was released towards the end of September 2017 received higher quality audio and visuals, as well as bugfixes and interface redesigns (notably, the port fixed the atrocious loading times that plagued the 3DS version, as well as minor issues like grammatical errors and typos in the dialogs), befitting a game being ported to a more capable device, albeit one with only a single screen that is incapable of autostereoscopic 3D, like Dual Destinies before it. And did we mention that unlike the 3DS release, these ports are available worldwide, and again, is cheaper than the 3DS version?
Pre-Order Bonus: There are two non-canon episodes exclusive to pre-ordered copies in the Japanese release. Pre-orders are also entitled to some alternate outfits for Phoenix, Apollo, and Athena (similar to Dual Destinies) and some pixel-art keychain charms of different Spirit of Justice cast members. These are all purchasable as ordinary DLC for Western audiences, with the costume pack having been free for those who bought the game before a certain date. Sadly tho, the non-canon episodes are not available to the iOS and Android ports.
Recycled Script: Most of the cases take plot points from Phoenix Wright: Ace Attorney while the ones that don't take from Justice For All instead.
"The Foreign Turnabout": A hapless youth is put on trial for the murder of someone close to him. Furthermore, the pedestal that the youth put said close person on breaks. Effectively, this is "The First Turnabout" without romantic overtones.
The defendant in both "The Magical Turnabout" and "The Rite of Turnabout" is a girl who is associated with magic of some form or other, just like in "Turnabout Sisters"... in fact, the defendant in "Rite" is the one in "Sisters". "Magical" has further similarities to "Sisters" in that there is bad blood between the defendant's family and the killer, and the defendant has a defense attorney as a (half-)sibling.
"The Rite of Turnabout" also has similarities to "Turnabout Samurai": What looks to be a murder is actually a self-defense killing, but it is covered up anyway due to the "killer's" connections to a group opposed by the local police force.
Even the Bottle Episode, "Turnabout Storyteller", is not immune as, like in "Turnabout Samurai", a prosecutor aids the defense team because said prosecutor is a fan of the defendant's work. There's also the fact that like Jack Hammer, Geiru Toneido is a performer who is so disgruntled with her station as a "lesser" performer that she attempts to kill her patron; unlike Hammer, she succeeds.
"Turnabout Revolution" takes from the finales of both above-listed games... each with a separate trial!
The first half's trial reuses a major plot point from "Farewell, My Turnabout": Maya has been kidnapped and the kidnapper threats Phoenix with killing her if he doesn't prove his client innocent in court. The main difference this time around is that the player, as Apollo, is in Edgeworth's role due to Apollo being Locked Out of the Loop until halfway through the trial.
The second half's Trial plays out very much like "Turnabout Goodbyes": from Nahyuta being taken off the case and (eventually) being accused of murder, with his superior being the female version of Manfred von Karma, to the discussion of the (attempted) murder of one of Nahyuta's parents, to an important figure in said past incident having to lose their romantic partner, job, and social standing due to that incident and being forced into a masquerade which unravels only when Apollo accuses this person of the present-day murder, to Dhurke providing Apollo with the resolve and information needed to take Ga'ran down from beyond the grave.
The DLC case, "Turnabout Time Traveler", features two siblings suffering a car accident. One of them dies. This is the main reason behind the murder both in this case and "Reunion, and Turnabout".
What Could Have Been: Going into this game the writers knew they had to take Phoenix out of his comfort zone so they could provide challenges for him while keeping his status of legendary lawyer in tact. In the end they decided to put him in a foreign country but one of the early ideas was to have Phoenix partake in underground criminal trials for the mafia where Phoenix would have to defend people accused of breaking the criminal underworld's own code of law. The judge, prosecutor, accused and witnesses could all be criminals, giving Phoenix a hard time trying to figure out who to believe and a lot of reason to doubt his own clients.
The game's writing staff included Masakazu Eguchi, who was a main writer on Capcom's Mega Man Battle Network series and appeared in the Battle Network games as Meijin Eguchi (Mr. Famous in the west).
The concept of the Holy Mother takes cues from both Buddhism and Christianity, the name "Holy Mother" itself was most likely derived from the Virgin Mary, while the character design was based of the deity Guan Yin from Buddhist folklore. On a side note, the similarity of both the Virgin Mary and Guan Yin has long been noted by the Japanese. The concept of not depicting the deity's face most likely came from Islam or old testament Christianity, where depicting the face of a holy spirit (or indeed, depicting a holy spirit at all) is deemed blasphemous.