I remember this issue rather clearly. There was a year (maybe 2008 or 2009) when UConn and Rutgers were both considered Top 5 teams, and they had already played each other three times (2 in the regular season and 1 in the Big East tournament) and had split the games. However, the Committee in its infinite wisdom placed them in the same region, to near-universal condemnation. The teams didn't want to play each other a fourth time before the Final Four, and the TV audience did not want to see a repeat of that game.
Then, a year or two later, the same situation arose with Baylor and Texas A&M, which was then in the Big 12. They had already played three times, and had to play a fourth time in the regional final. No one liked that either.
A few years after that, there was a situation where, if the Committee strictly followed its own rules regarding geographical proximity, UConn and Louisville would have been in the same Region and would probably have played each other for a fourth time. The Committee broke its rules and sent UConn to a Regional in Lincoln, Nebraska to avoid that outcome.
The general feeling was that in a national tournament, teams should play opponents from other conferences and other parts of the country, and should not be playing very familiar opponents whom they have already played multiple times. Obviously, if two or three teams from the same conference get to the Final Four, that can't be avoided, but (it was felt) it should be postponed as long as possible.
I completely agree with that thought. It is a sound policy not to allow teams from the same conference to meet before the Final Four if that is at all possible.