I do not understand this proposed change to the Terms of Service.

Stack Exchange [cannot revoke Creative Commons licensing rights](https://en.wikipedia.org/w/index.php?title=Creative_Commons_license&oldid=712992294#Drauglis_v._Kappa_Map_Group.2C_LLC) that have already been granted. Therefore, they cannot "un-license" any existing user profile web page content or other user-contributed content that has already been published under CC BY-SA.

However, that appears to be exactly the intention of this proposed ToS change. Hence my confusion.

If I have misunderstood, please correct me. If I haven't misunderstood, then the proposed new Terms of Service amount to an expression of licensor remorse, and in this regard are probably unenforceable and therefore somewhat pointless.