I'm sure I'm in the minority, but I'm not particularly afraid of getting sick on a cruise. Looking at the overall infection and death rates, it was much more dangerous to be in New Orleans this year than to take a cruise, and I'm not ruling out future visits to NOLa. I'm sure there are many more places that are also at least as dangerous as a ship, including just about every nursing home and every European city that relies on mass transit, not to mention NYC.
I am somewhat worried about getting quarantined for several weeks in a tiny cabin though, so I think the big things I need to know are not how they're going to prevent respiratory illnesses (which they can't), but how they're going to guarantee that ships are always allowed to return to their home ports and what provisions they have made for those who have been exposed to quarantinable illnesses. If those questions are answered to my satisfaction, then I'd consider a cruise if the itinerary was interesting enough. I think I'm pretty unlikely to find a "limited domestic" itinerary that would be interesting enough, so it's probably a moot point anyway.