How do ascians come into existence?

[Zojha]

That's a pretty clear and definitive claim to go back on. I would develop trust issues, lol.

It is, but on the other hand: We already had more than one visitor from Vana'diel, namely Shattoto and Iroha. In that sense, they've already gone back on that, as a cross-over requires some form of connection.

Whether it gets further than that remains to be seen. Could well be they go all like:"Evil guy X is creating a hole to another dimension, we gotta follow and stop him!" -> Venture to Ivalice in a similar way, except with a return option.

Personally, I ain't got the faintest. But it does seem like they're going to go back on that in one way or the other.