Speaking for myself, the only reason the term "mini MF" bothers me is it adds confusion instead of clarification. In digital parlance, the digital sensor sizes larger than 35mm/Fx are the new "Medium Format," at least for the entire contemporary digital world. To those that never chose to adopt or try them out, it does seem that there might be a sort of turn their nose up thinking that they don't offer enough over digital Fx to justify the investment, but of course they'd be wrong in that assumption... However and in their defense somewhat, the "gap" between 60mp Fx and 100mp MFx is narrower than it was with 24mp Fx; but that's a different discussion... My final point here is that I shot a LOT of MF *and* LF film in the day, everything from 645 to 6x9 plus 4x5 and 8x10; and when I got my first 65mp digital back, I got notably superior technical results to anything I ever got with my best MF and LF film captures. My 45mp back before that was superior to any of the MF film captures I made...
PS: Ironically, we also had "Large format" digital for a time being with scanning backs. They were a 3" x 4" sensor size and it slipped into the film slot between the ground-glass and camera on conventional 4x5 film camera. An entirely different topic of discussion again, other than my point here is that nobody ever referred to them as "Mini LF" digital scanning backs...