Hi,
Me and @tstellar are planning to restrict push access to the release branch (release/17.x) in the main repo. The main reason for this change is to avoid the PRs from the release repo will contain any extra commits that are directly pushed. This confuses the reviewers of these PRs.
It will also put a bit more control in the hand of the release managers, so we know exactly what goes in to the branch without monitoring the branch very closely.
The major downside of this is that very minor changes (like release notes) now also have to go though the normal backporting process. This is annoying but we think this is the better choice.
This will be implemented later today unless someone have a good objection to it. Please let me or Tom know in that case.