Only isolated from US gov't travel banned Americans freely visiting.

Next thing ya know they'll be telling us that the only cars in Cuba are 1950's Fords and Chevys.

We spent 2 weeks in Cuba 12 years ago and I would say half the people we met were from the US. Some came in through Canada and many more traveled through Mexico. They would charter small planes or there were what they called Ferries. Smaller Boats that made regular trips between Cuba and Mexico. These people had no problem booking in to any of the resorts or hotels. When we arrived we had to ask the customs officer to stamp our passports. We had to convince them that Yes, we really wanted a Cuban stamp.
We spent the first week at the Havana Hilton, where that Robert Redford movie was filmed. The second week we were at a resort, the only place we were told not to travel to was Gitmo.
I cannot over state how much we enjoyed the whole trip.

were told Americans were not allowed to stay in the beach resorts, because Americans could not be there strictly as a tourist on vacation. I went on a "people-to-people" tour. (Trump didn't close down Cuba until June 2019). When I was there, American cruises were still going into Havana.

This year, it's back to certain restrictions.
https://www.lonelyplanet.com/articles/how-us-travelers-can-visit-cuba

American citizens are not currently allowed to stay in Cuba’s government-run hotels or use most state-owned enterprises. Instead, it’s best to opt for private accommodation such as apartments, B&Bs and homestays (known in Cuba as casas particulares). Airbnb has lots of listings of accommodations that are open to US citizens.

US law states that US citizens can only travel to Cuba on a ‘general license’ based on one of 12 different approved categories, which include family visits, educational and religious activities, public performances and exhibitions, and the vague sounding 'support for the Cuban people.' Licenses are self-qualifying (there’s no long-winded paperwork), but you’ll be asked to state your category of choice in a signed travel affidavit when booking travel to Cuba. More details are available online from the US Treasury.

but the people we talked with laughed when asked about the restrictions. It was all "ask me no questions and I'll tell you no lies".
I can only tell of the people we met and their experience.
I do hope more people get a chance to visit Cuba, It is just lovely.