It more about being able to compare changes in future upgrades than if Visual Studio 2017 can open both format of files. Since the versions after 10.0.16 will use the new project format also. So that pushes to use the new format during this upgrade phase instead of another.
The Linked tool does look to get things at least closer than comparing the two diferent formats. Thankyou for confirming that was at least somewhat used to convert things.