I think already have some change on KYC.
Only old user can play without (KYC) before these updates and changes to their term & conditions. Right now users are required to pass (KYC) before they can gamble. Here some discussion:
https://stakecommunity.com/topic/89708-stake-forces-kyc-for-new-users/ on the discussion the @OP are being force to KYC after he was register to the site.
It is a temporary requirement that only new users have to do KYC but in future, I believe there will be mandatory KYc for all users, old and new users. Because KYC is part of AML and Stake.com as well as other gambling platforms will be targets of governments, DOJ and to avoid problems, they will force all users to complete KYC. Else users can decide to leave and find other platforms to use.
Like on centralized exchanges, to fulfill request from governments, mandatory KYC on all users is enforced by centralized exchanges. They don't exclude old users from mandatory KYC.