It's still possible for people from the US to visit Cuba. Trump took away the most popular way though. A bunch of organizers just went a couple of months ago.
https://www.liberationnews.org/young-people-from-the-us-travel-to-cuba-and-break-the-siege/
It's still up isn't it? https://www.reddit.com/r/Piracy/wiki/megathread/
Looks like they decided to make a backup here just in case