I think that's about the only way. But particularly considering that it would benefit another CONCACAF team (and even worse, the USA), means that I wouldn't expect them to strip his citizenship any time soon.
The statutes at least arguably contemplate the possibility. Who knows whether FIFA wants to wade into that political morass, though?
and still cannot play for the US. It almost sounds like the NCAA committee that handles the sixth year of eligibility requests.
As an example, Shalrie Joseph is a U.S. citizen who will never be able to play for the U.S. because he accepted a cap while he was in college. FIFA's almost-iron-clad rule is that if you play an "official" senior match (meaning a competition match, not a friendly), you're tied to that country, and if you play an "official" junior-level match, you're only allowed to switch once and only to another country you were eligible for at the time of the first junior appearance.
It would be more unusual for Alonso to be cleared to play for us, and if it happens, it will be entirely due to Cuba basically making him persona non grata for leaving Cuba. There really isn't a whole lot in the way of precedent for this situation, even though (as I noted previously) the FIFA statutes do appear to contemplate the idea.