I don't see this happening any time soon. College football is good because all regions are represented and people pull for their region, at some level. If you wipe out large swaths of teams and fans it becomes less interesting. The SEC and B1G walk a fine line between getting as big as they can to be profitable, and so big they actually diminish the product they are trying to derive revenue from. This is why I think the SEC, at least, slows down on expansion.
For example, would the SEC actually make more money by bringing in Clemson, FSU, Miami, and UNC if that means the ACC is destroyed? Maybe, but it's risky losing fans in the states and for the teams that don't come in.
What the post you are responding to is alluding to is the idea that it might be a better product if only those who truly can compete at the highest levels are in one Tier competing against each other, and everyone else is in another. We already have that with P5 and G5. Do we break up the P5 ... that's what the post is getting at. That may happen, and it may make sense some day. But that day is a long way away, IMO.