In the pre-day 1 patch version of Nickelodeon All-Star Brawl, Toph had a different taunt, where she raises her arms in the air. After the patch, this was changed to her waving her hand in front of one of her eyes.

Although Nickelodeon interfered signficiantly with the development of Nickelodeon All-Star Brawl, moveset and gameplay designer Thaddeus Crews has stated that he was surprised and grateful for the amount of creative control the game's teams were given:

Aang and Korra were first revealed for Nickelodeon All-Star Brawl on the Xbox Podcast with footage from their respective trailers. The CGI portion of Korra's trailer was not played, and following the reveal, Aang's trailer would be posted to YouTube, but not Korra's. This led some to believe that a CGI trailer for Korra was never actually made until May 2022, when a YouTuber named socks dude discovered the trailer on the website for i95Creative, the studio that edited the promotional material for Nickelodeon All-Star Brawl.

When it was announced that Nickelodeon All-Star Brawl's paid DLC characters were due to be revealed, it was with a tweet reading "Back to the lab again". Some theorized this was a tease for either Jimmy Neutron or Jenny Wakeman, both highly-requested characters with a technology theme. However, this seems to actually be a reference to a livestream by Super Smash Bros. Ultimate YouTuber GimR from two days earlier. GimR advertised the livestream for days prior, promising a new technique that would change the game's competitive scene, only to fail to actually start the stream due to technical issues. During the time he was live, he played a looping intermission animation depicting him as Dexter from the Cartoon Network series Dexter's Laboratory and playing the song "Back to the Lab" by Prince Paul and Wordsworth for over an hour. This mistake would become a meme within the Super Smash Bros. community for a short while afterwards. Ultimately, Jenny, Rocko and Hugh Neutron, the latter two not being related to technology, were revealed, and GimR would separately reveal the promised new technique, the "Slingshot", two days after the failed livestream.

In Jenny's showcase, her neutral air light attack is referred to as a "lingair". This is a reference to a tweet made by developer Thaddeus Crews prior to her reveal, where he questioned the appropriateness of the "sex kick", a competitive fighting game term originating from the Super Smash Bros. series for an aerial attack that stays out for an elongated period and slowly becomes less powerful, and suggested "lingering air" as a sanitized alternative.