Parmandur
Book-Friend, he/him
They've been swearing up and down that books they are putting out bow are meant to work with new Core, like the Starter Set coming out in August still remaining as the Stsrter after 2024.If they do Planescape and Darksun in 2023, they will then have done all (ish) the big settings in time for the 50th Anniversary Core. To me, this seems like more evidence that 50e is going to be only slightly iterative - it might be a bit of a departure from 2014 5e, but it won't be much of a jump from what we've seen lately.
There's just no way (IMO) that they'll put out Planescape, and then make it obsolete a year later. Anything that's in there will have to jive with 50e. So... that said, that means this UA is the kind of stuff we're likely to see going forward.
That all of the recent UA for books suggests a new united approach to Feats suggests to me that they will sell what changes they do make as just consolidation of recently published options.