I read somewhere (don't ask where--I don't remember) that the delay might have to do with current hotel offerings and unknowns regarding how much more they'll be able to open up. Unless they're able to open more hotels, many would be booking DVC through Disney since that's what's open, but DVC members need to be able to book theirs first, so they are holding off until at least the 11 month out mark...at least.
The other problem, and much more likely to be the main reason for the hold up in my opinion, is what to do with the 50th when they've lost so much revenue. The parks will need to cut plans, but what should they cut? Can they make a profit off of their big anniversary? And what sort of events can they safely hold?
Anyway, I'm keeping my fingers crossed we hear something soon. I had hoped we might have news October 1, but that's come and gone with nothing.