I suspect this year is going to end up as quite the mulligan across the board for basically all travel-related companies. If I had to guess, Marriott will play "follow the leader" and act in the vein of what other chains (Hilton, Hyatt, etc.) do.
With that being said, I think there will probably be a bit of pressure across the board to at least pull back on status requirements a bit and/or offer a double-nights promo or something like that. 55 nights for Titanium (75 minus 15 for the CC and 5 from the 50-night award) isn't that hard when the world is functioning normally. Doing so with the world totally borked for 2-3 months starts getting tricky, even for a Marriott-exclusive customer, and if there's a secondary outbreak in the fall (which I think a lot of us are "pricing in" mentally) that calculation goes out the window. Note that IHG has already dialed status requal requirements back by about 25-30%; I think dial-backs in that range (maybe a bit more) are perhaps more likely than just extending status. A double nights promo in the summer is also plausible.
Part of the issue is that while there are cases of folks being able to move big trips/stays, there are plenty of folks for whom trips simply can't be moved (e.g. PTO requests are locked to given dates) or would get cut back.