Poloniex is the biggest exchanger, and of course they have anticipated the problem, I'm sure there will be no problem and I'm still confident of storing bitcoins there.
Poloniex's statement is a bit ambiguous but sound reasonable. They have no way of knowing if BCC is gonna be good or not.
What's interesting is bitfinex and poloniex stand on lending.
Bitfinex will give BCC for those who lend.
Poloniex will NOT give BCC for those who lend.
And that is a big problem. I stop lending and will move BTC out of lending account first just to make sure.