There's an episode where they find a huge underwater pyramid that has ancient Greek writing on it. A character gets possessed and starts speaking Greek. It turns out it's The Temple of Minerva built by Neptune. Now if you had a thing for mythology, like I did, as a kid you probably notice those are the Roman names of the gods. And Minerva is a black woman. This is in the early 90s.
This "replacement rot" has been going on for a long time
Literally every part of the 90s was diverse. Any show you turned on had a super mixed up cast in some way. From Power Rangers to the "random kids on the Burger King bag." Its almost surreal to go back and see how common place it was compared to how much you remember.
I think the difference is, and why it doesn't jump out to people as much, is because it didn't feel as malicious. Like, it was the frog slowly boiling but it felt like at least partially there was some sincere attempts at racial harmony being tried for.
I'm sure the Elites at the top and all the various Jews and Commies were pulling strings to make it happen, but the lack of overt malice made it far less egregious and offensive then compared to now.