The anti-heteromorph racism in MHA is completely realistic and I am glad they addressed that it would be that way, especially considering everything else being addressed as the core plot, but it feels like the acknowledgement came out of the blue. We didn't really get to see it build up at all.
There are plenty of heteromorph pros like Selkie and Gang Orca. Teachers like Hound Dog. Students like Tokoyami and Kouda. Even with Spinner we didn't see anything until suddenly the League took out that CRC group. I don't think anyone even used the term "heteromorph" until season 6.
Don't get me wrong, this show is fantastic at build-up for the most part but this is one part where it just... wasn't there.
-- Izumi // she/her
P.S. I'm farther in the show now (on season 7) and I'm glad there's hindsight about Shouji, and the pressure for silence does make sense. I do feel like they should have planted more seeds though, even without anyone really acknowledging it.