"For The Kids" was Trademarked in 2019, but was used by The Penn State Dance Marathon (THON) long before that. THON is the largest student run philanthropy in the nation, raising $13.75million during this past event in Feb 2022 . All of that money goes to the 4-Diamonds Foundation, which supports families suffering with pediatric cancers. They have been using "For The Kids" at least since the late 90s. Each year, there is a "Line Dance" that all the dancers learn. The first year I danced in it (1998) "For The Kids" was the final line that we shouted (the tune was to disco hit "Knock on Wood" by Amii Stewart), so their prior usage goes at LEAST until then. However, the reason they filed for trademark was in the news up here. They were having problems with cheap t-shirt makers selling knock-off merch, diverting the money from the charity. In order to send them cease and desist, they had to file for trademark. And while the Philanthropy is entirely student run, the venue and IP is owned by the university, so they were the ones that had to file.
It's a crappy situation caused by crappy people. If there weren't scammers, they never would've had to file for trademark and Extra Life could also continue to use the phrase. Realistically (and I do NOT speak for THON or PSU), I doubt they'd have any issue wth ExLi using the phrase, as long as they weren't selling merch with it, and even then, I bet if someone actually reached out to them, showed some of the ExLi stream segments and the Dell Children's Hospital wing, they'd probably work something out.