I have an update for those who rented DVC points and don't yet have park tickets (and I think this is inconsistent with information at least one other person posted here since yesterday):
I just used the chat function to ask questions about my January 2021 reservation, which was made by a disboards.com DVC member I rented points from. According to the CM I chatted with (and I took screen shots), I fall into the category of people who have a 2021 "resort only" reservation but no park tickets yet, meaning I'll be able to both buy tickets and make park reservations starting 6/24. I asked him what would happen if we pushed our trip back further into 2021, and he said I would have to cancel the park reservations and rebook. If the tickets I needed for the hypothetical later-in-2021 trip were more expensive than the original ones (because of a more expensive "season" like April), I would just have to pay the difference.
I gotta say I don't love having to spend another $5k or so (there are 10 of us) of non-refundable money this far in advance. I may just hold off and wait and see how things go. If Disney still needs to manage capacity in January, and the experience is still limited in terms of no parades, fireworks, and the million other things they've cancelled, chances are much better than 50% that we would try push our trip back anyway.