Enevhar Aldarion
Hero
It can't be none of the above, anything outside that list would be a first visit, not a revisit.
Every time I rad those tweets, I somehow tuned out the "we've already covered" part about the revisit.
Oh, and the line about not being MtG settings could just be referring to the two brand new ones and not the revisiting one. He did a lot of vague wording in those tweets, so keeping the MtG books on the list is valid.
So my opinion is it is not something we are just getting this year, or even last year. Too soon for a revisit. I think I will vote for an updated and expanded book to replace SCAG. That book was outsourced to another company to put together, so they would probably like a newer version that was done totally in-house. And then they can put in all the new optional race/lineage rules and some of the stuff from Tasha's and other books, since they like to always include some reprinted material. This book may even include references to the greater world and locations outside the Sword Coast, setting up future products in other regions.