How about we look at how the other 1 seeds get sited. Since UConn has had the top seed the most they often have the "privilege" of getting placed in the closest site, which has usually been in the Northeast. The second No 1, using the NCAA's policy at the time, would be placed in the closest of the remaining sites and the third 1 seed would get the closest of the 2 remaining regions while the 4th seed gets what's left. If any west coast is picked as the west regional (and I can't remember even one year when the west region was anywhere else) then Portland is the furthest region for any of the 4 one seeds, leaving it open for the PAC12 team that is the highest seed, whether it be a 1 or 2 seed. In all the other regionals the 1 seed got there because of their S curve position, not by a geographical anomaly in the seeding procedures.
I'm not saying this has been done deliberately, just that it is an edge, however big or small.