If one follows the best practices for them[1] (installing apt-listbugs and apt-listpackages), one gets information of bugs and API-breaking changes before performing the upgrade, and can decide to pin the specific package as needed, and it will automatically get released when the bug is solved.
This is thanks to how the Debian packages treat bug reports, and the debian/NEWS file. I can't believe other distributions get it so wrong for so many decades.
Plus, these 2 distributions (Testing and Unstable) get all the automated QA usual from Debian: autopkgtest integration tests, piuparts, lintian, reproducible builds, policy conformancy..
It seems it's no coincidence that gLinux from Google, rolling release, and in TFA, is based in Debian.
[1]: https://wiki.debian.org/DebianUnstable#What_are_some_best_pr...