Latin choirs are classic Final Fantasy, yes, but not a particular trend in Japanese videogame music (not to my knowledge, at least). As for subtlety, I'd say it's on par, if not just a bit less subtle than popular western RPGs like The Witcher and Skyrim, and certainly much more subtle overall (important word) than games like God of War and Doom. That said, IMO, subtlety in music is not used enough for it be a trend in either. The Last of Us is the only OST that I would call subtle overall.

I don't really think it's that distinguishable since they can easily draw inspiration from each other..

Personally, western music is in general, way too boring or generic, with some exceptions of course.Japanese videogame music just stomps everyone in style, quality and variety.

This is one of the gripes I have with western games in general.