Yeah, the Japanese servers are physically located in Japan. You can't just make them, NOT Japanese servers in the blink of an eye. The latency caused by distance would still be there, and the fact that most players are speaking Japanese would remain.
Additionally, while they have some capacity to add more servers, in the short term this wouldn't do much good. Too many players are invested in their characters now, they won't re-roll on a new server easily. That's putting aside the fact that Square has no idea whether or not the player base will remain in place after two or three weeks. A number of players probably won't even stick around after the free period after all.
No, the real solution is do things like implement a proper queuing system, and a mechanism to auto-kick idle players. That'll solve 2/3rds the problems in the short term, and in the long term the gradual reduction in traffic would deal with the rest.
