I can't see how it will be allowed, in either the VGC or smogon.
afaik vgc allows them, but they also have awful accuracy.
The match in this vid
>>31376230 requires a bit of setup and the uploader even admits that the team is gimmicky and only won three out of the seven matches for the competition.
But a no guard fissure machamp that needs no setup to be effective, or perhaps an agility baton pass, that can sweep like 80% of all pokemon?
Even if you can bring stuff to counter it, every single team would now have to bring a machamp no guard counter, and the entire meta would instantly revolve around the four armed muscle head.
