San Juan has no facility capable of holding transiting airline passengers for 7 days in quarantine before they fly on to mainland US. Perhaps my imagination is incapacitated, but i can't believe anyone intends for Puerto Rico ( or St Thomas, for that matter), to be the quarantine ward for the rest of the US.

Hey, I know, I know, what " government" thinks and says is rarely without a hitch in the get-along, regardless of the country or custom.