Last year, the NCAA made some changes for teams moving from the FCS to FBS in football. They removed the 15,000 average attendance requirement (which would open the door for a team like UC Davis), but they bumped the application fee to make the FCS to FBS move from $5,000 to $5,000,000. Plus, there are now 42 more football scholarship slots in FBS than in FCS (plus another 30-40 on the women’s side to satisfy Title IX).
I’m thinking that was a big deterrent for UC Davis (and any other current FCS school) to bring football over without a real guarantee of recouping that with TV money. Outside of somebody like NDSU or a private school in the FCS with a big money alumni base, I think we may have seen the last round of FCS to FBS transitions for a while.