PyYAML 5.4 is the last planned release with Python 2.7 support. With 5.4's conversion to setuptools, the python_requires metadata is now being properly generated into the sdists and indexed by PyPI, so Python 2.7 users will be properly directed to a 5.4 release by, eg, pip install pyyaml without needing to pin a version.

Dropping 2.x support will allow us to remove the bifurcated 2.x/3.x codebase- a significant maintenance hassle, as well as simplifying the Windows wheel builds (making them easier to migrate to GHA for a single CI platform).

If major bugs/security/whatever issues are found, we've not ruled out the possibility of doing additional patch releases on the 5.4 codebase, but those would be evaluated case-by-case if/when they happen.