I'm not that interested in the fighting over schools of tennis teaching. But I'm totally convinced that using high speed video, in which Yandell has been a pioneer, is the big breakthrough in understanding high level tennis.
For example, I think there is a "new" forehand as performed by Federer, Nadal, etc. I'm not knowledgeable enough to know that there weren't early antecedents, but the heavy "pat-the-dog" motion at the end of the back-swing along with the straighter arm stuff seems to be different than what I recall seeing of Lendl or even Agassi. However, this is not something that I think Wegner or anyone else can claim credit for (can they?).
So, I think the game is still evolving, and that the way pros actually play is shaping what is taught because we can see things in ways that wasn't possible before. We don't need to rely on the pronouncement of gurus, and the younger generation probably doesn't care as much about who claims to have "invented" what the pros are doing.
Hopefully, I haven't gone too off course.