I think this change is great, but this really only becomes news again once all major LTS are shipping with at least Python 3.7, right? No one can really use it in code they plan to distribute at the moment. Maybe I am underestimating the amount of Python code that is meant for internal or personal use only.
Many apps bundle Python along with their app, either within a container image or as a complete portable copy distributed with the binary. We've been building FROM python:3.8 for a few months.