How is the end of support for python 2.7 next year going to impact arcmap 10.6 which is supported until 2024 and uses python 2.7.14 and Numerical Python 1.9.3. My gut says that this could be painful, e.g. no pip and no support for many popular packages.
Python 2.7 just won't get any updates... it will probably continue to be around much like Cobol did.
I would suspect that it will continue to be the python version for the ArcMap series... changing it to python 3.x would likely to cause panic amongst the user community.
Python 3.x (currently 3.6.x+ can be used quite nicely in ArcGIS Pro. Put your efforts on it as the development environment. The Anaconda package is a great option, although I personally don't like the 'Clone' thing (see my blogs) but it is there now.
You can pip install within the conda/python environment, but things are lot cleaner if packages come from one distribution. Some packages have pip and conda install options.
Development wise... time to move forward
I am looking forward to pro and python 3.x for sure. But we are stuck at 10.6.1 for years because of other software dependencies. We were at python 2.7.3 and 2.7.2 (arc 10.1 1 and 10.2). It was problematic, e.g. pip stopped working and we had to go to wheel files, web scrapers stopped working because of changes to ssl... etc. I am just unhappy with the situation.