I know when I booked a Disney+ special cruise for last month (I booked it in July), it was specifically mentioned to me at least twice that the sale was final and unless I tested positive for COVID there would be no refunds, no price adjustments, no nothing. You should read the specifics of any discounts you are interested in using to see their stipulations.
It worked out great for me. I ended up cruising on Disney for what I consider to be a bargain, after having experienced it.