As much as I hate bittrex, I think that a lot of the coins are removed because of blockchain issues. And that is out of the control of bittrex and the coins are probably worthless anyways even if someone did claim them.

It's not really a delisting of markets, but rather removal of already delisted markets from wallets.

The only problem is that people may have unverified accounts that they are consistently unable to get verified and they are foregoing some funds here. But hey, that is one of the risks of storing money on exchanges. Though bittrex could have handled this better by at least allowing these unverified people an extended amount of time to get themselves verified before they forfeit their balance.