They could easily detect if you have a altered client. That is one of the purposes of gameGuard. As of right now no they won't ban you. In the future, if they actually do something about the bots, they might not differentiate between harmless pk2 and a bot program.
Mostlikely though they will ban bots in the future by tracking player movement in game just like REV6.
Also since pk2 editing is becoming popular they will probably warn you first if they will start blocking accounts. They will say you have a modified client and need to delete and re-download the game, thats all.
***EDIT***
I was using logic, Joymax does not, so who knows what they will do
