Regarding renegotiating, the difficulty is: with whom are you going to negotiate? There are LOT of parties, and every one of them marches to the beat of a different drummer. Even assuming you could get all of the unions lined up (I'm dubious; it's a tall order), each show has an author (or a few) and many of them are dead. You would have to persuade the person controlling the rights separately for each one. And let me quickly add that we are not talking about a huge amount of money and not everyone would want their work seen in this way. So I would not start lining up quite yet. Even in unprecedented times. (Oh, and one more thing. If in fact this is a stop gap until things are up and running again, then there is going to be a lot of push back that letting this genie out of the bottle is a bad idea.)
I think more possible (especially in the context of what I have been saying about Broadway and getting tourists back in seats) would be filming new productions. There will be a period, potentially lengthy, when the unions will be satisfied that it is safe for their members to work again even though there will not be enough business to prompt producers and investors to take the risk. (In other words, if Spring '21 is deemed "safe," there will still be a huge lag in getting tourists back in the requisite numbers. I have said this could be Fall '21, but some others think we are talking 2022.) I am optimistic about putting this behind us, but not about doing it soon. I have opined on this and related subjects in other threads so I won't say more here.