Off the top of my head, SpongeBob SquarePants, Danny Phantom, Fairly Oddparents, The Big Bang Theory and It's Always Sunny in Philadelphia all have jokes, if not the main plot point of the episode, that are just mocking the existence of LGBTQ people.
I went to a very right-wing school in northern Indiana (I estimate that about 70 percent of the voting-eligible staff and students voted for Donald Trump in 2016) and people saying "gay" to mean bad, along with frequent uses of slurs, continued to be prevalent until about 2012. After that, there wasn't much until about 2016, when blatant was transphobia was the dominant viewpoint.
At the graduation in 2017, there was a transgender woman who graduated as part of my grade who was forced to wear the male graduation uniform.
:gui-trans: