When I renewed my pair of tickets for this coming season...I think it was May? The option to make three installment payments for the ticket price was offered (no interest)---which I took advantage of. Tickets are now fully paid, my TN Fund donation is charged to my credit card in 12 equal installments---and that hasn't halted.
I don't see UT automatically refunding any of the donation and will probably want to 'credit' my account for future games rather than send a refund---but they might offer that option. I wouldn't want to be the person making the final decision on logistics for allocation of seats----TN Fund donors are ranked very carefully on a point system, from 1 to about 11,000. (That's accounts, not number of tickets held) I'm old and have been a donor and season ticket holder for 34 consecutive years, have great seats in Sec. V, row 26 on the aisle. My TN Fund ranking is 1702. For this reason, I'd expect SOME deference is my game choices, assuming there are games and fans can attend; however, I believe younger fans, younger donors with lower rankings (higher ranking number), etc. should also have access to tickets.
UT has often used a sort of lottery system for away game tickets that were in heavy demand. (I recall only 5,000 tickets were available for the Notre Dame game in South Bend---and over 10K requests. I was at The Miracle at South Bend. What a memory!) Everything is in such a state of flux; I wouldn't even venture a guess as to how this will eventually 'play out'.