A service is obliged to send at least a notice to user email addresses and account notification dashboards about the changes in the terms. This is the standard procedure I know about. Now whether Rollbit sent out a notification or not, we can not tell at this moment in time until we hear out Rollbit's side of the story.
Personally I don't read TOS from time to time and sometimes I'm not even checking emails from a casino as most of them are promotions. Well, in this case, if it's a standard procedure, OP should have already receive the email but that changes could be effective immediately and now he has to withdraw his funds. I think it's just fair that his withdrawal will be release if he can't comply with the KYC because he is afraid that he will fail, but that doesn't mean the funds will be withheld by a casino.
I believe Rollbit has a good reputation so we might hear from them soon, especially if OP will put more evidence to his claim.