As far as I know Debian intends to have no plain `python` on the default PATH once the python2 packages are removed, so that it will be up to the system adminis

As far as I know Debian intends to have no plain `python` on the default PATH once the python2 packages are removed, so that it will be up to the system administrator to decide where that will point. See eg https://lists.debian.org/debian-python/2018/05/msg00063.html https://lists.debian.org/debian-python/2018/05/msg00063.html from the Debian Python maintainer. (That's a year and a half old, but I haven't seen a message go past suggesting they've changed their minds.)