I think they predate that by a lot, and I don't think it was anything to do with the ultra wealthy.
IMO people talking about political correctness often miss an important point though: that what's believed to be acceptable is largely derived from an actual philosophy that is changing over time, which develops and evolved as society processes new ideas in the background. That processing happens online and in communities, in books and essays, in art, etc... and then everyone becomes aware of its new conclusions over time.
All of the philosophical work underpinning the 2010s was very much around in the preceding decades in a less crystallized form, but it rose to prominence on the back of various crises and scandals. I can attest, for instance, that the underlying philosophy of social justice predates Occupy, because I first heard it in college in 2009-2010ish, and it wasn't new then. By that point it had a life of its own already, as people people subscribed to it (because it gave them a framework to feel like they were being a moral person).
Aside, I think people overpredict manipulation of culture by organizations and elites because they aren't sufficiently imaginative to see how it could happen organically. Ideas have lives of their own, largely based on the problems they solve for people: how to feel moral in their life, how to put into words their moral intuitions about justice and duty, etc, and (rarely, much less than people think, but definitely sometimes) how to have social power over other people.