If one wants to do substantial reading on the subject, there are a number of specific recommendations about how ships can safely resume cruising. Here is a link to that report.

Link

And a blurb from Cruise Critic for the Cliff's Notes version. Link

Personally, I think the bubble deal is stupid.

BTW, I think the 'no sail' order has been extended to December 1 now, but not sure. It appears that one thing that will happen for sure is that folks will ONLY be able to leave the ship on designated shore excursions.