I think your take is not only wrong but 100% backwards. The playoff is the only reason the regional trend of CFB could possibly be reversed.

Right now the SEC champion and Clemson are hogging 2 spots every year. Under the BCS you only have two spots. Those spots will be disproportionately taken every year by those two teams, and regional interest outside the South will fade.

But because of the playoff, the following teams outside the South either made the playoff or had a shot (generously calling Oklahoma Southern, even though it’s not, because most non-Southern people would regard it as such):

Ohio State
Minnesota
Penn State
Wisconsin
Oregon
Utah

These are all teams that were either in the playoff (Ohio State) or at some point were seriously in the discussion before either another team on the list eliminated them (Utah, Penn State, Wisconsin, Minnesota) or they eliminated themselves by shitting the bed (Oregon).

None of those teams have a chance when there are 2 slots available. The polls would not have put undefeated, defending national champion Clemson at #3 in a world where 2 spots were available. And as we saw, LSU jumped Ohio State in the final analysis. Very likely that without the playoff, an undefeated non-Southern team is shut out of the title picture; and certainly a half-dozen non-Southern contenders don’t get their shot.

You are correct that CFB has been trending very regionally over the last few years. The South has a recruiting edge that will likely never be topped short of widespread institutional collapse that forces local recruits to look elsewhere. But that edge alone obviously wasn’t enough to make the South dominate the CFB world in the early and mid aughts, after demographic shifts had given the South its fertile recruiting grounds; elite programs across the country could contend by building off power bases in the Midwest, Texas, and California.

I would love to see USC become prominent again. I think that would help greatly. I think even Miami would help, despite it being the most southerly big city in the country, since it’s not really regarded as “Southern” but as its own entity. But really I’d like to see USC become prominent again, and I’d like to see the Big Ten get one.

The problem with your analysis is that the playoff makes that far more likely than the BCS would.