On the subject of Ivan, quite a few predicted that he would be a medieval knight since in the source material, his Sentai counterpart was a samurai.
Kendall becoming the Purple Ranger after Albert's tenure. Kyoryuger, the casting sides that Saban Brands released, or the color of the glasses were dead giveaways.
Quite a few predicted Tyler's dad, James becoming the Aqua Ranger. The big giveaway was the scene where James gets crushed by the boulders in the flashback scene of A Date with Danger, since when he got crushed, a bright aqua light emerges from the rocks that crushed him, indicating he bonds himself with the aqua energem.
A lot of theories surrounding season 2 suggested that Sledge wasn't killed in the crash, and that he would be the Greater-Scope Villain of season 2. Sledge's survival was confirmed via the synopsis for the episode Worgworld.
Kendall shares her first name with Danny's love interest in two episodes of Power Rangers Wild Force. Her name is very similar to Kendrix Morgan, the first Lost Galaxy Pink Ranger who was also a Hot Scientist. An interview with Judd Lynn, however, says that the two are unrelated and that he didn't realize the similarity until he was told.
Going even further than that, Yoshi met with some of the Sentai producers, who were so impressed that the producers for Hikonin Sentai Akibaranger and Kaizoku Sentai Gokaigerdubbed him the real-life version of their shows' respective Promoted Fanboys, Nobuo Akagi (Akiba Red) and Gai Ikari (Gokai Silver).
The subtle KyoryugerShout-Out in episode 3 (Chase singing a song with the same tune as the opening theme "Vamola! Kyoryuger" and Koda whistling the song toward the end) was apparently something Yoshi and James Davies (Chase's actor) planned out together and got put into the show.
Promoted Fanboy: Aside from Yoshi above, there's Michael Taber (Green Ranger) — he's a longtime fan of Power Rangers and even went as Magna Defender for Halloween as a child!
Real-Life Relative: In addition to José Luis Orozco voicing Keeper in the Mexican Spanish dub, all of his children have major roles in that dub. Luis Fernando voices Chase the Black Ranger, Andrea voices Shelby the Pink Ranger and Alejandro voices Sir Ivan the Gold Ranger.
Short Run in Peru: Brazil is getting the Supercharge episodes - and the spoilers contained therein - three weeks ahead of broadcast in the USA. In Australia, the episodes air one week earlier.
Teasing Creator: Before the Aqua Ranger's official debut, scattered throughout the season were various minor characters with cyan motifsnote Tyler's missing dad's shirt (he turns out to be the one), The Dino Café waitress serving the Rangers as they discuss the Ankylo Zord, Julian the photographer with his inner T-shirt, the snatch thief in New Zealand with his bike and Heckyl with his Skunk Stripe and innerwear.
Prop Recycling: Several of the monsters in Sledge´s prison appeared somewhere in the past seasons. One of the most obvious is Necrolai/Vancuria (difference unclear) in Wishing For a Hero as she is visible all the while Heckyl clashes with Sledge.
The retreating monster Heckyl kills in When Evil Stirs has the head of Dumbbell Bot from RPM
Early casting calls show that Riley was originally named Ryan, Tyler was originally called Lucas, and that Kendall was going to be called Kiera. All three were changed due to beingpreviouslyused.
Riley's brother Matt was originally the Graphite (then called Gray) Ranger, rather than Prince Phillip.
The Deathryuger/Kyoryu Navy suit was going to appear in the show as the Talon Ranger and Heckyl was going to become that Ranger. It's been theorized that the reason this fell through is because production was unable to get the rights to the suit (things that appear only in Sentai movies have to negotiated separately unless they happen to appear in-show, like with the Spinozord) or they didn't have the budget for it having spent it getting the rights to Snide's suit which was also movie exclusive.