You mean Jynx, Jase?
I think it's a combination of the Jynx racism row, and possibly some connotations with epilepsy. Still, it seemed a little bit strange.
Similarly, in all Pokémon centres apart from HG/SS, Nurse Joy says "We hope to see you again.". In HG/SS, she says "Please come back again anytime.".
There's probably some sort of EU ruling affecting all English-language versions of the game: It was the EU's fault that the Game Corner was removed.. and no doubt, they'll eventually get the whole gameplay system changed so you can only play for one hour each day.