I might be projecting a bit, but it's not like he's been hiding his disdain for Western animation and we're putting it together via crypitc remarks. He's saying all this out loud in interviews, particularly after the Black Knight pitch leaked and he made his immense frustration with Sony not moving the project forward public, to Entertainment Weekly, no less. He specifically cites the success of KPop Demon Hunters and Demon Slayer under Sony, while they left him out to dry after the dog nuts debacle.
https://ew.com/genndy-tartakovsky-the-black-knight-origins-leaked-footage-exclusive-11827802
And he wouldn't be the first person to put his frustrations with his career on the screen or page:
The very last thing Jack Kirby drew for Marvel before bailing (the first time. He would bounce between the Big Two over the years, until he finally got a job doing the Super Powers cartoon and toyline, which let him finally collect royalties on his creations). The anger is palpable at Stan and the rest of Marvel.