There's no mystery to me. Roth was a regular visitor to Cuba. It seems to me that the meeting was held on the balcony of Roth's hotel/casino which was probably one of the ones that he said would be turned over to others after his death. He would have had a regular suite there.
You really don't think that Michael, the most powerful Don in America, is simply going to grab a taxi at the airport like any tourist. Ola was his escort and guide since Ola knew his way around Cuba physically and politically.
Hold on there. Thats my point and question. Since I think we agree that the meeting of the businessmen with the gold phone, was at a different location, and that Mike was on his way to the balcony meeting, was Ola with him? Why didn't he travel with Roth? Keep in mind Mike never really spent a lot of time or did any sightseeing when he was on business trips.