It would take 5 minutes for "Tristan" to put up a notice on the poloniex website regarding the situation, and regarding deposits/withdrawls.

Why has this not yet been done to avoid this ^^^^^ frustration?

No actual refunds has been given for BTC deposited after the incident. I'll believe it when I see it. And we can breath a short sigh of relief when the above parties have their funds back. (Assuming that all those deposits will have been refunded and not just those of the persons who happen to post here or on http://poloniex.freshdesk.com/support/discussions/forums/1000078491 like coinmarket did to keep the con game going)