Look at President Obama as an example; when he ran for President in 2008 and 2012 he was opposed to gay marriage and publicly stated he felt marriage was only meant to be an institution between one man and one woman. But by 2013, he suddenly "evolved" (his word) on the issue and now supports gay marriage.
There's a difference between supporting/opposing gay marriage and just thinking it's okay for people to be represented and seen in a public space. People can definitely evolve, but you're comparing legal rights (with Obama) to just the right to be seen (in a movie). I'm fairly certain that most children have seen a gay person in their life. A cartoon including a gay person is not an endorsement, it's an attempt at normalization so kids don't grow up to "other" people who aren't exactly like them.
But this has devolved into the Strange World thread all over again. Nothing but cuteness, Disney references, and people discovering their power to be found here in Wish.