16 is better than 4, but it does open up a lot of issues without specifics about who gets in and how, or a change in scheduling rules. Even now, I don't see any benefit for a strong SOS for OOC games. Bama gets a cakewalk of a non-con and no one bats an eye. Texas sets itself up for a trap game like Maryland rather than an FCS opponent and puts another game of real mileage on its players, while Bama gets to have 3 soft opponents with no repercussions from the committee. The system already sucks.
If you take all conference champs then Bama gets rewarded with another cupcake, while Texas risks a lower seed, due to playing a more difficult schedule, and could end up facing a Top 10 team in the first round rather than a G5 patsy. If you could go to 16 and it is based on rankings, then OK, the results are a little less cut and dried, but you still have no scheduling integrity. If you got to 16 and only give the P5 autobids, you likely end up with a lawsuit from the G5, so it is probably committee-ranked or bust.
16 would be more tenable if playing FCS teams were outlawed and a codified SOS component was added to the ranking criteria. Going back to a BCS-style formula isn't perfect, but the committee selection concept has proven corrupt.