It doesn't really make sense:
1. We will be crediting users who had BTC in their account balance at the time of the fork with matching BCH.
2. We have not yet determined if we will be listing BCH as a market on Poloniex nor can we commit to supporting BCH withdrawals right away.
If I get BCH but can't trade it (on a trading platform..) and can't withdraw it (on a trading platform..) then what can I do with my BCH?
As they mentioned "nor can we commit to supporting BCH withdrawals right away", which means initially it will be disable for a while like for most exchanges and once they have the stability and confidence in network they will enable withdrawals.
I expect they will definitely list BCH in markets as well, something which all major exchanges will do sooner or later.