It's a problem. When you consider how much experience they have due to playing the game for a long time, on top of how many of them there are. I would say there are easily 5 times the korean pop vs english.
Just look at the rankings - and they are starting to pvp non-koreans out of high level mob areas. This game release is basically just a new Korean server, but with a side dish of global players learning the game for them to snack on.
The global release will not be successful is this continues.