A colleague of mine created a new Differential Revision today. I was added as the reviewer. Herald added a project as Blocking Reviewer of which I'm a member. When I requested changes to the revision, the project was no longer a Blocking Reviewer but it had become just a normal reviewer.
So far, this isn't really a big deal, because the Revision is still in the state of Changes Requested and nothing bad can happen.
But we also have a workflow, where our interns first review each other. The same project is added as a Blocking Reviewer to those reviews and when the interns have accepted the revision they add one of the project members as a reviewer to do a final check. When the project member now requests changes to the revision, the project becomes a normal Reviewer instead of a Blocking Reviewer as well. But because the intern is still listed as an accepting reviewer, the revision goes to the accepted state, and the author can land the revision without acceptance from any member of the project that was supposed to be a Blocking Reviewer.
Version information of our instance:
phabricator 8f7983a5be3a56db5b79dc7c3a0eb470f1d7ca02 (Sat, Mar 25) (branched from b4effdf26c3e7d5de0d010cf14626c5d8d404e04 on origin)
arcanist 60aaee0ed3f5a1e4384ac7d7f2efd2c64cecbe44 (Sat, Mar 25) (branched from d1db9a72b552151613a918e3d49fa72433387a68 on origin)
phutil b133c277014868d476f08b4ebecde2ea795509e4 (Sat, Mar 25) (branched from c0bc116bedc895fd617799a13549f8707edfd3fb on origin)