This year will be the first year that the tournament is expanded to 6 teams, rather than the traditional 4. This is because of the addition of the new Conference Carolinas.
The champions of the four conferences will automatically make the tournament (MPSF, Conference Carolinas, EIVA, and MIVA). The remaining two at-large teams will be selected by the NCAA Men's National Volleyball Committee when they meet following the conference tournaments.
The top-two seeded teams will have byes during the first round. Based on the present ranking, that would be Loyola and Stanford, but all of that can change with the results of the MPSF tournament. I don't expect Loyola to lose their conference tournament.
Just my guess, but I think if BYU wins on Thursday night, they'll make the tournament.