There has been some consideration of an 80-team field with the NCAA. I think it is a good idea. One article I read mentioned that when they first went to a 64-team field that it comprised 22% of the teams playing D-1 basketball. Today, only 19% of teams playing D-1 basketball make the tournament. If they would go to an 80-team field, then the number again goes to about 22% of the teams making the field. It is relatively easy to add 16 teams. If they consider 16 regions of 4 teams, all this is adding one additional team to each region.
What would bother me though is if this idea opens up 13 more slots for the Power 5 and only 3 slots for mid-majors. There would need to be something in play that mid-majors and low-majors are guaranteed a number of slots in some particular way. I certainly don't have the answer on how to guarantee those parts.