I've also encountered the legacy -> new account conversion. Conveniently locking up all my funds as well, I also tried to do basic verification which failed instantly due to a typo I suppose, if its even going to work at all. (My hopes are small for Bittrex now) Meanwhile support wont reset the basic verification and is trying to force the enhanced verification on me, and not just resetting my basic verification. Maybe completing the enhanced verification would be justified had I wish to stay with the platform, but all I want is my small but worthwhile funds made from mining back and sent to my hardware wallet.
But this is just too much to ask.
Hope everything works out for those who have been fucked by Bittrrex.
Decentralized platforms are going to take off.