Recently a tag arcgis-pro-2 was created on a question where one of the answers referred to the coming ArcGIS Pro 2.0 release.
I am not proposing the introduction of dot release tags for ArcGIS Pro (for v1.x or v2.x). In fact, should we consider making these tags [arcgis-pro-1.x] and [arcgis-pro-2.x] to make it all-inclusive?
Extra note, I just found a comment on Geonet (dated Feb 27, 2017) by Esri staffer Robert LeClair that mentions planned release of ArcGIS Pro 2 for Q2 2017 (not far away!), also with an interesting note about the future of ArcMap:
You are correct that ArcMap 10.5 is fully retired December 2022. With that being said, there will be an ArcMap 10.6, 11, 11.1, etc. so the actual ArcMap product will not be retired for many, many years to come. Customers may continue to use current and future releases of ArcMap if they wish. But with that being said, product development, new functionality, etc. is being invested in ArcGIS Pro. Future ArcMap releases will have some new functionality but will be focused on product stability and bug fixes. The plan is for ArcGIS Pro 2.0 to be at functional equivalency as ArcMap with a release timeframe of Q2 2017.