I could be wrong, but the reason the rumor mill is churning, as Mongo mentioned, would be related to whatever FIM is doing in WSBK, etc. That rumor mill has been churning repeatedly in the direction of there no longer being a 1000cc class at all. They've been spit-balling the NGSS class as the premier class and the 1000cc bikes would fall by the way side. I am just guessing the decision may be pushing from the manufacturers who seem to be selling less and less superbikes and more and more smaller displacement bikes. NGSS may likely become the younger generation's premier class race bike outside of prototypes.
Something else that could be funny is how club racing tends to adapt slower (with good intention) to allow those of us paying our way to keep running the same machinery and have more advance notice to make adjustments and not have to always go buy the newest expensive thing. That means there will likely be a time where the premier class of MotoAmerica might run a slower lap time than the premier class of club racing! I mean the kids on NGSS will probably still be faster, but it "could" happen, haha.
Anyway, with Liberty Media taking control, I'm sure there will be at least some influence depending on which direction they want to take WSBK as a commodity as well. If MotoGP bikes "might" be a little slower starting in 2027, it follow suit that WSBK might get slower bikes for its top class also... whether STK1000 or NGSS.