I dont think that to much of importers would change back to XBOX, if at closing of PC/PS2 xbox would ahve had same content as JP PSU some would ahve gone there for sure. But soem are now on the JP PSU for a while and got some nice stuff and i guess msot of them would want to start all over again on the XBOX servers. It would take pretty long to restart the 3rd for some people. It's a guess and jsut my opinion not gonna say a lot of peopel would change, but im sure not all importers would change again.
Anyway, I would be happy if XBOX would have same content as JP PSU, since we all paly the same game (kinda even if its different versions) and it would be nice to see Western version be updated often and properly