GC once said that if they were going to give MS to all dps classes, they might as well just make it an aura in arenas. I'm starting to think it might be better for the game if they just did that. It'd certainly be easier to balance.
GC knows about as much about arena as John McCain does about winning elections. Because of this, she is also completely incapable of understanding the developers intentions when they do things and at best she acts as a mediocre conduit to devs about specific issues.
She's much better about PvE concerns, but I would take anything she says about arena with a grain of salt.