Not under the current status quo. This is the type of thing a fighters' union could demand.
Frankly, I don't particularly care for the shots covered in logos. They look bush league. In fact, I think it'd be kind of cool if Venum had specifically colored shorts for each country (I know some fighters stay true to this like the Poles and Brazilians), but if it was regimented with a flag patched onto the waistband, I'd dig it (keep the champions in black shorts though). HOWEVER, regarding the sponsos,if the UFC is going to muddy up the canvas by having logos splattered all over it, then yes, let the fighters market themselves too.