The short answer is “we have no idea.” It’s likely that there will be more freedom of movement for Cuban players and, thus, more of them will be able to come to the United States and ply their trades. But the details of how all of that will work are unknown, obviously.
At one point in history Fidel Castro told Major League Baseball officials that he envisioned a situation where there were MLB academies in Cuba like there are in the Dominican Republic. Of course (a) that happened in idle conversation between Castro and some baseball bigwigs during a goodwill series; and (b) the level of exploitation that occurs with young Dominican players was probably not too well known by Castro when he was talking. Say what you want about thawing relations between the two countries, but if the academy system is anything, it’s Capitalism with a capital C, and I question whether even a normalized U.S.-Cuban relationship would go for that at first.
Likewise, it is almost certain that Major League Baseball does not want all Cuban players to be free agents because, to say the least, Major League Baseball hates free agency. They’d prefer some sort of draft, in all likelihood, but that doesn’t seem like something Cuba would be in favor of given that the country still likely wants to maintain its top league — Serie Nacional — and not experience a full-blown talent drain to the north. So, what happens?
Ben Badler of Baseball America — perhaps the most knowledgable guy around when it comes to Latin American baseball — has some informed speculation on the matter, and it makes all kinds of sense given the competing interests at play:
What’s most likely to happen—and what some prominent Cuban baseball officials are pushing for—is some type of system that’s a cross between the relationship MLB holds with the Mexican League and the posting system it has with Asian foreign professional leagues such as NPB and the Korea Baseball Organization. When teams sign Mexican players, they are usually targeting 16-year-olds (like Dodgers lefthander Julio Urias and Blue Jays righthander Roberto Osuna, among many others), the majority of whom are already affiliated with Mexican League teams. The teams train and develop those players, sell them to major league teams and take a 75 percent cut for themselves.
While not the best thing in the world (my personal preference is for free agency, everywhere, always) it’s a decent compromise given all of the factors involved and is probably the least destabilizing system for Cuban baseball in the short run.
Of course none of this happens if Congress refuses to drop the embargo with Cuba, thereby making it illegal for U.S. companies such as baseball teams to give any money to anyone if it would end up back in Cuba.
And the incoming Congress is totally gonna do that, right?