Poloniex doesn't support bitcoin cash.
Should I move it?
Also what happens to electrum wallet after the forks?
They never said they weren't supporting it. They said they may or may not support it. And yeah, you should get it off if you can.
Poloniex sure get's most investors have an heart attack, I think they will surely check what's gonna happen on the August 1 and then take actions before that if what's is good with bitcoin right now, I think they are thinking of precaution first before entering a solid support on what is really gonna happen, and yes definitely you will need private key on holding your bitcoin, but if you don't have any just sell you bitcoin if you are worried for your money.