not sure about the strategies here but maybe a better approach would be to kill support for unsupported version of windows in a major release
since I guess python 3 was a complete rewrite of python2 (at least the low level side I assume it was) 

and it would be easier for people to remeber (eg, if I have to rewrite my app because python4 has a major language differences I might as well drop support for older OSes in it), eg, python2 works on XP, python3 works on vista and up, python4 works on windows 10

for instance, I didn't even know you can run python3 on XP, I always thought that python2.7 is the last version that would run there

and since the code to support windows 7 is still present (almost, just the installer change would need to be rolleed back and some compiler declaratives: 
https://github.com/python/cpython/commit/0b72ccff56fb47e14f7b1f6590eafff8d104c229
https://github.com/izbyshev/cpython/commit/6a65eba44bfd82ccc8bed4b5c6dd6637549955d5

I see no reason to touch it (it probably just stays there serving its purpose) and when python4 comes along (if its a rewrite then windows 7 hacks (would just not be written anymore)