From what most places have been saying Multiday tickets will be back in some format but there are have been rumblings of ROF not returning (that particular rumor was also thrown around pre-pandemic due to the Sept crowds increasing). General consensus is that the multi-day ticket options will go on sale later than usual this year as they continue to gauge what kind of crowds they're going to have. Also rumblings about express being a day of only upcharge, meaning they won't sell express passes early and it will just be a first come first serve option each day of the event have been discussed. I think one podcast was hypothesizing that multiday tickets would only be valid on Wed, Thur, and Sun to try to keep crowds down on Friday and Saturday nights.
General feelings that are as the US inches back to normalcy and if we don't continue to get spikes after each easing of restrictions, they will probably go "business as usual" and sell the same tickets that they always do. Of interest might be the fact that they just raised AP prices by $50 so the insane numbers some people were throwing out for express options being 50%+ higher this year might have a shred of truth to them.
BUT, these are all just rumblings and unsubstantiated. Just throwing out the different info I've read/heard. If I had to venture a guess, I would think that Universal has like a "best case scenario" plan laid out, with 10 different contingency plans ready to go. I think we might be waiting longer than usual to get the multiday ticket options and maybe even longer after that for an express upgrade. I think you and I might be buying ROF passes while keeping our fingers crossed for a while hoping that an Express upgrade for the ticket becomes available.