Note that 3.9 is the first release to not work on Windows 7 anymore, which is still rather widespread. At the same time, to the end user, it offers very little over 3.8.
My point was: keeping support for Windows 7 at the cost of basically nothing seems sensible for now. That leaving some niche of Windows XP, Windows 98 or MS-DOS users does not change the balance. Few still use these platforms to begin with, and even fewer would benefit from a portable Python app.
Well, each user, so you are well within your rights to define any of your systems as mission-critical, if that's how you consider them.
There is no Council of Critical Missions that needs to evaluate applications. :)
Python 3.8 has already reached the point where it’s only receiving security updates - not other bug fixes.