Thanks for the report, guytp. I'm sorry. I kept meaning to post here. That was full of useful information.
Here's an interesting development. Costa Rica will allow US visitors to return in September, but it will be on a state-by-state basis. For the time being, residents of New York, New Jersey, Connecticut, Maine, New Hampshire, and Vermont will be allowed to visit. (Driver's licenses will determine that.) Only non-stop flights from approved states may fly to Costa Rica. Effectively, that means flights from EWR and JFK. A passenger from, say, Ohio, could not connect at EWR and fly to Costa Rica, because they don't live in one of the approved states.
Massachusetts, Pennsylvania, and Colorado are being looked at as the next possibilities. Under this system, flights from MIA, ATL, and IAH are not coming back anytime soon.