Yes, Poloniex delisted Steem unfortunately.
From their website:
Poloniex is beginning the process of delisting Pascal (PASC), Steem (STEEM), Navcoin (NAV), GameCredits (GAME), LBRY Credits (LBC), and Clams (CLAM). Here are some important dates to keep in mind:
- October 15th at 16:00 UTC: trading of PASC, STEEM, NAV, GAME, LBC and CLAM will be disabled
- November 15th at 16:00 UTC: PASC, STEEM, NAV, GAME, CLAM withdrawals will be permanently disabled
RE: Weekly report: How much STEEM is stored on the exchanges? - October 24, 2019