We're going to allow Mupen64Plus for emulator submissions but we will require the emulator window to be shown for both Mupen64Plus and OpenEmu.

Hey, could Mupen 64 also be allowed ? Because Mupen64Plus is a pain to use, and the "engine" is pretty much the same I believe ?

No

Mupen64 (not Mupen64Plus) has TAS functionality, so there's no way it will ever be allowed.