> I was against removing the module in the past because parts of the macOS API still used (on probably still use) classic MacOS style paths.  Most if not all APIs are by this time deprecated, which makes it less and less like that anyone will use macpath going forward.

bpo-9850 has a scary title: "obsolete macpath module dangerously broken and should be removed". Extract:

   "Even if one did have a need to use the obsolete old-style paths, the macpath module is currently practically unusable for anything other than simple character manipulations of the path.  Nearly all of the functions that actually call OS routines are broken in one or more ways."