2022 FCS Playoffs To get an autobid you have to have six teams in your conference. I assume that means six teams that are eligible to be in the playoffs.
Jacksonville State is ineligible for the FCS playoffs because they are transitioning to FBS. That leaves the Atlantic Sun with five teams. The reborn WAC only has five eligible teams as Tarleton State is transitioning from D-II to D-1(FCS). There is something called the Atlantic Sun/Western Athletic alliance in which a computer ranks the teams in both conferences and an auto-bid goes to the team that comes out on top of the rankings. That happens to be Eastern Kentucky from the Atlantic Sun.
Ivy League does not play post season football. (Not unique in the Northeast. The teams in the D-III Northeast Small College Athletic Conference don't compete in post season football either.)
Winners of the MEAC and SWAC meet each year in the Celebration Bowl. Their choice, probably more fun in any event.
Don't know about Mercer, but two teams above them from the Southern Conference did get in. Samford is in with a first round bye and Furman is also in.