Secondly, you don't just need to believe whatever welcome note you see on a platform, be it a casino or any other platform that requires you to entrust them with your money. Always make time to go through their T&C and see what they say about your account registration, withdrawal, and deposit, and see if they truly do not care for KYC.
I just did a quick search and found out that some other members of the forum have already figured out the KYC part and quoted it in a thread where someone asked for it. I will quote their terms and conditions for you to see where they clearly state they will request KYC.
Quote from: https://justbit.io/policy/kyc/
Know your customer (kyc)
After registration process the User shall provide JustBit with valid identification information under these Know Your Customer (KYC) procedures. The User shall undergo KYC procedure after completing the registration of User’s Account and:
Before first withdrawal of funds irrespective of the amount;
In case of a deposit for the sum equal to or exceeding 2000 euros or its equivalent in virtual currency;
In case of depositing in amount of 7 500 euros (or its equivalent in virtual currency) or more (by several installments) by the same User during a month.
After registration process the User shall provide JustBit with valid identification information under these Know Your Customer (KYC) procedures. The User shall undergo KYC procedure after completing the registration of User’s Account and:
Before first withdrawal of funds irrespective of the amount;
In case of a deposit for the sum equal to or exceeding 2000 euros or its equivalent in virtual currency;
In case of depositing in amount of 7 500 euros (or its equivalent in virtual currency) or more (by several installments) by the same User during a month.
You can either give the KYC a try if you want to get your withdrawal out of there or you can let it go and don't hope on getting the money out. Maybe the previous withdrawals were not yet up to the amount where they requested KYC, and this your last request could be what clocks it up to that. Maybe that's the reason for the KYC request, just my guess.