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.