At the moment (next few weeks) I can't commit to much, but I may be able to do a some after that. At that time I'd need to know what the plan is before knowing if I'm able to do anything.

IMO, Python 2.7 should be used (optified if not already) for now. Ideally I'd like python and python2 symlink to point to 2.7 when migration done. Any modules/apps/debian rules/etc should then specify python2 or python2.7 not python to avoid issues and more work later if later migrating to default version to python3.