As I said on AH.com:
I say it could be called cultural genocide. In some cases, it will very clearly be Roman culture running roughshod over the natives and absorbing them. It is pretty indisputable that the Romans, even if they tacitly allow existing languages and the like, are very clear on 'you need to be Christian and I'd prefer if you speak Greek'. One could also argue it isn't cultural genocide using the fact that the Romans aren't going to be forcing people to give up everything other than needing to be Christian as a starting point.
I'm going to acknowledge all viewpoints here, and there is a solid argument to be made that what they're doing is cultural genocide in the name of integration.
That said, the Roman style of cultural assimilation is a substantial and measurable improvement over the methods historically used by the rest of Europe. Pre-Christ Rome's methodology of telling conquered peoples that as long as they obey Roman law and pay their taxes on time they can do whatever was a key component to Rome's success, adding 'and at least
pretend to be Christian in public' doesn't really change much. Especially under these specific circumstances where the Romans have some
pretty convincing evidence that their God is real enough to pick an entire city up and plonk it down on the other side of the planet to save it from heretical invaders, which is a pretty convincing reason to convert by any metric.
(Incidentally, have the Romans figured out where they are yet? I
believe they should have sufficient knowledge of astronomy to determine approximately where they are compared to where they were, but I'm not certain.)
So yes, while what the Romans have done\are doing to the local native populations
could be argued to be cultural genocide, it is a
very inoffensive form of such, and substantially better than the native populations could expect from literally anyone else.
Hmmm, the Spanish being more invested in the Caribbean and its various plantations has interesting (and very unpleasant) implications.
There's going to be a
lot of dead Africans in the Caribbean, even more than OTL, I reckon.
With a much stronger native presence on the Central American mainland and Cortes' Wild Ride presumably going to faceplant spectacularly, I imagine the Caribbean islands will be an even more exciting place, as they will be much easier to colonize than Central America and thus more valuable.
The knock-on effect on the Transatlantic Slave Trade that this will have will be interesting, and also probably horrifying, because it's the Transatlantic Slave Trade and that is always horrifying no matter what happens.