Billing Displacement: In the full trailer released on October 21, 2017, Steve Yeun is billed before Scott Menville even though the latter plays the lead character. This is averted in the show itself, where Scott Menville is given top billing.
Smokestack is not the first crime boss that Clancy Brown has voiced.
Scott Menville voices Jake Armstrong, and is once again a teen hero with exceptional combat skills.
"Gangs Of Old Town" has Eric Bauza voicing one of the gang leaders, who's shown to have a strict sense of honor. He's done this on another Hasbro show.
Dawson Casting: Teenage characters voiced by adult voice actors.
Fake Mixed Race: Ricardo Perez and his father seem to have both African and Hispanic heritage, yet their respective voice actors, Ogie Banks and Phil LaMarr, lack the latter.
The Parks' and Dashtis' VAs hail from several different Asian countries, as opposed to only Korea or Iran. Averted for the voices of Nathan Park (Steven Yeun), young Riya Dashti (Kathreen Khavari), and Riya's aunt (Khavari again).
Not everyone Eric Bauza voices seems Filipino; for instance, Victor Cook has referred to the Gentleman as a British Indian.
Iranian Kathreen Khavari voices Rook's mother in "Rook's Story".
God-Created Canon Foreigner: The tie-in comic book, written by Chris Wyatt and Kevin Burke, introduces the monstrous Mantoids, the Extreme Hazard Unit, their stern leader Agent Rathjani, Ricardo's old friend Alistair Reynolds, and his sister, all of whom never appear in the series itself.
In Memoriam: At least one episode with Stretch Monster bears a dedication to his VA, Miguel Ferrer, who died from throat cancer 10 months before the cartoon's premiere.
Missing Trailer Scene: The teaser shows Multi-Farious punching through a billboard for the Original Stretch Armstrong doll, then getting into a fight with the new Stretch and his teammates. This doesn't really happen in any of the episodes with Dr. Robertson as Multi-Farious.
Somewhat confusingly, the show alternates between David Kaye and the late Miguel Ferrer as Stretch Monster, and some episodes even have both of them together.
"Rook's Story" has Tony Mirrcandani replace Eric Bauza as the voice of Aadarsh Dashti.
Having Yvette Nicole Brown and Jon Heder as villains is quite surprising given that they usually voice more good natured characters.
To a lesser extent, casting Josh Keaton as Gabe, who's a jerk jock like character, is a bit unexpected.
Posthumous Credit: Miguel Ferrer always gets his proper dues for voicing Stretch Monster, even in cartoons containing recordings from both him and David Kaye, and/or debuting well over a year since his death.
From Miles from Tomorrowland , this show has Eugene Son, Will Wheaton, Felicia Day, Tom Kenny, Stephanie Sheh, and Grey DeLisle Griffin
Quietly Cancelled: The second season streamed in September of 2018, and as of 2023, there's still no word on a season 3. So, it's safe to say the show was silently given the axe.
Spoiled by the Cast List: IMDB posted season two episode titles and cast lists, including the names of some of the Flex Fighters' new enemies, well before the season aired.
Time-Shifted Actor: Riya is normally voiced by Nazneen Contractor, but her younger self is voiced by Kathreen Khavari.