Correct, VS commandline calls MSBuild. They're using MSBuild, they just don't know it.
That seems like an inaccurate description of what's happening: http://stackoverflow.com/questions/11932164/what-parameters-...
They're using MSBuild, they just don't know it.
Given the age of projects I've worked on, and that it's unclear whether MSBuild is involved in VS's C++ compilation, I don't think your assumption is correct.
The change was explicitly to make it so that a C++ project file was an MSBuild script.
Visual Studio absolutely uses MSBuild for C++ projects.