I'm pretty sure we're opening to the same extent as canada or europe, but Puig still had to hire smugglers to take him to Mexico rather than booking an air Canada flight. I don't think opening means that people will be allowed to defect
That's not the full picture though. What opening DOES mean is MLB potentially being able to go in and say hey, we'll build baseball training facilities and provide free gear all over the country, in exchange for you allowing baseball players to enter the international draft. Similar to what MLB has done in the DR.
There was zero incentive for the Cuban government before, because not a single dollar was supposed to flow back. Also, there is speculation that the Cuban government allowed Yoan Moncada to leave freely, given that he was in Guatemala on a valid Cuban passport, so it's possible they're already loosening up there.
Also, part of the shadiness of the Cuban baseball player path has been that they had to establish residency in another country to obtain an American work visa, due to the diplomatic relations (or lack thereof) with Cuba. Hopefully it will be less shady now that ballplayers are possibly able to just apply for work visas directly from Cuba.