iirc it’s basically to appease the Cuban voting block in Florida who are against the regime in Cuba (because they got kicked out/lost property/whatever). This group holds some amount of sway in federal elections on account of Florida being (having been?) a swing state.

I believe Obama was in the process of mending the relations between the U.S and Cuba, and then Trump got into office and promptly reversed it as a giveaway to this group that now votes Republican.