honestly you probably won't be riding fast enough to notice chatter in the board at speeds. not in control at least.
what i was talking about was float in powder. yes, powder is freshly fallen snow. with a shorter board you could have problems keeping the nose up, keeping your speed up, and generally staying on top of the snow.
just be aware that in these situations you can stay on top better by setting your stance up more towards the tail of the board.
the board you got is fine for what you will be doing with it.