I understand that most of the time, exchanges will allow you to make a final withdrawal if they are going to prohibit you from using their services for a compliance-type reason, such as KYC, with the only exception being that they believe you are on some kind of sanctions list that would prohibit them from sending you money, such as OFAC, which leads me to:
I see no reason for anyone to continue using Bittrex. They're many other (and better) alternatives.
I wish.
It's not the case for the CEXs today. When you get the KYC card, it's either you comply and get back the access to your funds or you don't and it's theirs. You can read countless threads about this when you look it up. And exchanges usually don't tell the reasons for it or make it vague like "we detected a suspicious activity" so we don't know how sensitive their system is when it comes to this.
Additionally, this is bittrex who imposed mandatory KYC without prior notice which locked thousands of users out of their account and has the mandatory source of funds. We can't really expect them to be that lax when it comes to KYC... or any other compliance type
I have been asked about the source of funds for the coin I trade with on coinbase dozens of times, and dozens of times, they have accepted my answer without asking for supporting documentation. I am surprised that Bittrex is asking for supporting documentation for the source of funds question.
Some CEX are laxer than the other which makes them relatively better
