I think @andybons has resolved the issue of some of us not being able to remove TryBot-Result votes recently, see #29285 (comment). E.g., I have that ability now:

Do we still need the trybot-result-changers Gerrit group for anything? I don't believe @andybons's solution used it.

I'll leave this issue open to decide what to do with trybot-result-changers group, but otherwise I believe this is resolved now.

I created a new group may-remove-reviewer that is the umbrella permission for removing reviewers, ccs, and labels. We can either make trybot-result-changers a child of that group or remove it.

/cc @FiloSottile FYI, since you're changing or considering changing Gerrit permissions.

@dmitshur Is this still not working as intended?

The current status of the issue is:

I'll leave this issue open to decide what to do with trybot-result-changers group, but otherwise I believe this is resolved now.

If we don't need an open issue to track that task, this can be closed.