Haven't read the whole thread, but I think maybe WotC is searching for a way to refresh the IP, and in a forward-thinking way (while they're "ahead" rather than "behind"). I've heard some remark that "D&D" is in need of a bit of a revival, in terms of world/setting/flavor. The core IP is great and "evergreen," but there are only so many times that you can rehash old settings and stories, much of which is rather dated. So at the very least, they need to find new vessels for the IP.
Consider how many fresh and innovative RPGs have come out over the last decade or so. In a way, I'm reminded of D&D in the 90s: you had a flurry of innovation in the late 80s-early 90s alongside the Indie boom. By the late 90s, D&D was anachronistic and decrepit relative to RPG development as a whole.
The comparison only goes so far, of course, as D&D is still thriving, at least in terms of popularity. But the current wave seemed to peak a couple years ago, and regardless of book sales on the 2024 core rulebooks, they'll need some fresh inspiration to revive momentum, imo.
And it may be that they're forward-thinking: how can they revive and fresh while they're doing well, rather than after they've been slumping for a few years?
Finally, I think it is hard to quantify just how important settings are to IP. I once remarked back in the day that one reason that Pathfinder was so strong was Golarion: it gave a central world for all to relate with, if only to illustrate in a living way what Pathfinder was about. WotC doesn't have a singular world; there's the Forgotten Realms, but it is pretty much in stasis. Perhaps they are taking more of a "Worlds of D&D" approach, with multiple ways to interact with multiple worlds. But to do this, they have to churn out some worlds, give living examples of what D&D can be.