Bittrex has long required KYC.
Bittrex has long since been trying to act like a bank. Bittrex has further shown this by evolving to be a fiat-based exchange rather than a crypto-based exchange.
Fiat based exchanges will be subject to KYC because accepting fiat comes with additional steps.
I'm reading a lot of horror stories about Bittrex even from already KYCd people. I don't know if Bittrex is dodgy or just overzealous but my guess is it's better not to find out and go to one of the other many exchanges.
CEXs are not doing fine in this market and bittrex is getting out of the news. No top project from the exchange, no volume, reduced users and was never mentioned with project that had a huge price movement either in a day or week. If it continues this way, bittrex might be one of the project that will be swept off in the next bear market.