Alright, I just did a live video so nobody could accuse me of fudging it and found a few things. So yes, it happens, it corrupts your registry for all future plugins.
BUT
The answer was not to deny that it happens, but instead one of two things:
1) that the installer (now?) gives you a chance to choose the VST default install path
Or 2
2) Go to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\VST in the registry editor and change it back
This video shows it all...its long, but that is in the interest of transparency.