Those are webinars and a few isolated studies or lit reviews (which often contradict each-other and/or aren't reproducible), not a large body of scientific evidence. I'm not saying that they won't eventually have a large body of research to support something like that, but also, they might discover that people who eat lean red meat are actually slightly better off, because anemia is one of the common side-effects of ADT, and red meat is more effective than supplements for raising your blood iron. 🤷 (Note that I'm a vegetarian, so I have no personal stake in this.)

Right now, it's still a guessing game. Some doctors will have strong personal opinions either way, but the body of proper scientific evidence isn't there yet to resolve the question.

Note that there *is* a demonstrated correlation between eating excessive amounts of red meat and colon cancer, so reducing red meat consumption could be helpful if you don't want to deal with a second cancer battle. But I don't see general scientific consensus yet on a link between any dietary element and prostate cancer progression (again, writing as a layperson, as, I assume, you are too).