You can go a step further. Instead of merging anything, you can tell the ci to merge it. Then ci can make a "merge-test" branch, run all the tests on it, and if they pass, then ff-merge it to master for real. No need for "good chance" or rebasing just to keep up with master.
It does take some extra work though, because GH and others don't really support this out of the box.
It does take some extra work though, because GH and others don't really support this out of the box.