I don't get the logic behind your battletested thought.
Generally it might be true that finally python 3 is now the default for new projects but that doesn't mean that there will be a switch to python 3 as default enviroment. There are still a lot of base libs which are not ported to python 3. Most often nobody has interest in porting them. Some are, but then often as a complete rewrite, which are not backwards compatible.
Until Python 3 is the default env it will take a few more years.
In 3 years, Python 2 will not be maintained anymore. It should really not be used for anything important in 18.04 LTS anymore, because that'll need to be supported for longer.
But thats my opinion of course. We need to move the industry forward eventually and 95% of useful plugins/modules have already been ported.
It's time for py3 as a first class citizen.