No. Poloniex is a centralized exchange, with past history of trouble during big moves, support can take literal weeks to respond and they blocked Steem/SBD withdrawals for a very long time. With the vast offering of exchanges nowadays, Bittrex, Open Ledger, etc, unless you have a very compelling reason to stay in Poloniex, you should consider moving away from it.
RE: What's happening to Altcoins as Bitcoin Crucial Dates get closer?