Not that the public is aware of.
Elecbyte has been absent for years again (since shortly after the 1.1 release)
Mugen is NOT open source, so only Elecbyte and their team can modify the Mugen program.
This is THE reason there are so many people programming Ikemen.
Ikemen is the only current hope of a new Mugen version (even though it is technically Ikemen, not mugen).
Well worth the switch for all the bells and whistles