New Disney XD summer preview. It features Big Hero 6 and I'm pretty sure the bits with Hiro and the video game and Fred with Bluff Dander are new. I even rewatched "Hardlight" to make sure the former wasn't from that episode.
I'm not exactly sure the show will have a Marvel crossover given how it doesn't exactly want to have any kind of shared universe. Plus, Phineas And Ferb was still big even when they did those crossovers with Marvel and Star Wars. Big Hero 6 The Series has a more niche appeal (where there's a fanbase, but it's not that vocal).
Yeah, going to have agree with Frontier. They will never publically admit it, but Big Hero 6 is clearly now a Disney property, not a Marvel one (yes yes, all Marvel is Disney, you know what I meant).
Just look at how BH6 have been treated in the comics. When the movie came out, there was no new shiny collection of their old stories and after the fact they have disappeared completely. Compare that to how after Into the Spider-Verse, both Spider-Man Noir and Spider-Ham got big "complete collection" trades of their comics or how Guardians of the Galaxy have been part of every big comic storyline after their MCU debut.
Honestly, some of the shows that aired (or currently airing) on Cartoon Network don't even warrant the TV-PG rating, I'm talking shows like Teen Titans Go!, DC Super Hero Girls, Clarence, Uncle Grandpa for example. TV-Y7 at least.