"Third-party Python libraries and frameworks are going to start dropping Python 3.6 support. And that means if those libraries have a critical bug, the fix might not be available on Python 3.6."

For python libraries included as distro packages, aren't source packages identical between python 3.9 and python 3.6 ? Is there anything more than a rebuild neccessary ?

And for pypi libraries, is there any extra work the upstream maintainer has to do to support 3.6 ? What would dropping support for 3.6 mean from a library developer ?