Logging into AdSense this morning 12 hours ago, then again awhile ago, I again received the same pop-up.

Organise your sites New Beta
Site management

The Site management feature allows you to build a list of sites and sub-sites to use in site-related actions, such as setting up site-level blocking rules.

Go to Site management / Dismiss

I go to Site management and merely get a listing of previously "allowed sites".

For what purpose?