Why did MadVR get moved from Standard to Full release package?

I'm curious why MadVR is no longer part of the standard release. Is EVR considered to be just as good now?

It did not get "moved". Full already contained it. It got removed from Standard to increase the contents difference between Standard and Full. If you want to use madVR, you should use Full version.

The default renderer in all versions of the pack is "MPC Video Renderer".
MadVR has never been the default renderer, for the simple reason that it can be quite difficult to configure (in order to benefit from its advanced capabilities), and that it may not be very suitable for running on older hardware.