I should start right at the top: the Vegas 16 tournament, which is in its first year, ended up with a field of eight teams. It was supposed to be a 16-team tournament (hence the name!). All eight teams are mid-majors. This is not what they had planned.
It's fair to wonder what is unusual about this whole thing. There are a couple other low-profile postseason tournaments that feature nothing but mid-major programs. On the surface, this is just one more addition to that crowd. Thing is, though, the Vegas 16 organizers' ambitions were a lot higher. A LOT higher.