There's no reason for them to be open right now. I don't think it's permanent. Yet. They'll try to stay alive for sure. The problem is the next major release on the schedule is Soul, which likely gets moved, and then things like Free Guy, Monster Hunter, Dune, and WW84 that are still around in December. I'm gonna bet most of those December movies get moved to 2021 and theaters will go on an indefinite close again. The problem is the uncertainty about reopening. They tried it now and it didn't work already. I don't have a ton of optimism that even Spring will be great in terms of returning to the movies and the thing is, people have to be willing to go.
The problem is, if Studios wait too long to release their big movies in theaters, the theaters might not be there when they need them to be when we're on the other side of COVID.