Imo, western players migration to west version from JP version is probably not even a concern of whether this west version will be successful or not, nor it will affect much the english population in JP version. The least that players who play in JP servers do are having a new account and try it out, and be a hero to all of the new players (teaching new players, be (or acting like) the expert, etc.,).

This is more targeted to:
1. those who want it to be in the west but never/barely touched PSO2 JP or can't even get passed the captcha boss
2. players who don't even know what PSO2 is all about.