I voted yes because I've been soft inted for banning other champions when released...although it doesn't usually happen anyways. Not a lot of people are that upset with it from my experience(unless they actually hover the pick). Almost always, the released champions are just OP, and the enemy is probably going to try and pick it also. Senna looks pretty OP too, there's too much going on in her kit. Just her passive alone has like 3 effects.
I don't ban new champs in normal draft ever, though. For me, normals are where you go to either have fun or learn new things.
Honestly though, I stopped banning pretty much entirely. There's something around 150 champions in the game, and banning just one seems pretty pointless to me. I'd rather learn to play against/with it. There's too many characters worth a ban anyways.