I don't see why it wouldn't work. I assumed whether the process worked or not was dependent on:
a) the original language of the games the Pokemon came from, and
b) what generation the breeding was done in, not the original generation from which the specimens came.
If it doesn't work, then I'm guessing the reason is maybe because migrating a Pokemon screws with the data of what language game the foreign Pokemon came from in the first place? Thus assuming the language of the game it entered, rather than exited?
But this is all background theory from what I have long assumed to be the case. I have no proof on what is correct. If anything behind this take is not clear to you, let me know and I'll try to explain what I believe to be the case.