Ahhh....noooo. It's not punching up. At all. It's punching down. The writers are in a privileged position that none of the gatekeeping grogs they're punching have. Those gatekeeping grogs don't have a platform akin to official D&D modules that go out to millions of people, much less one that surpasses it. That's the definition of punching down. I don't think it's punching at all, but if it is punching, it's definitely down. Some punching down is acceptable, like messing with a heckler at a stand-up comedy show. If this is punching at all, it's that kind of punching. The gatekeeping grogs taking it upon themselves to try to stop the game from changing or denying newer fans a place. If this is anything, this is the writers stepping in and telling the geezers to cool it and that the kids are all right.
Nah, if it's anything, it's punching up. Recall that for the most part, grognards are aging middle-class white guys who have -- and have always had-- the luxury of time (and usually also money) to waste on RPGs, as well as a secure environment and similar people to spend that hobby with. These grognards typically are not ground down by relentless poverty or abuse or discrimination. And while some of them may well have been picked on as kids, they now enjoy life in a society that has not only accepts overt "nerdiness" and pointless leisure, but even celebrates it.
This isn't blackface or chainmail bikinis or something. Most of the people "offended" by this are neither truly harmed, nor even truly offended. For most of these complainers, IMO, this a fake "internet controversy." And I mean that literally: if this Thaco the Clown had appeared in a book in an era
without Twitter, exactly no grognard would have given it a second thought beyond a slight scowl or a quiet chuckle, depending. If they noticed it at all.