1. It's weird to drop from D1 to D3. Whole division in the middle to consider.
2. From the beginning of college sports' transition away from amateurism, I've been saying this. In the end, I think there will be a small (maybe as many as a couple dozen) Elite division. The vast majority of D1 football schools will be in a second level that more closely resembles CFB from 25-30yrs ago.
My thoughts have adjusted slightly, however. I originally thought the Elite level would be 15-20 teams max and did not think PSU would be one of them. I was seemingly wrong about the amount of money PSU alums appear willing to shell out. So now, here is my prediction...
There will be a P2 of the SEC and B1G. Some percentage of current schools will eventually be relegated to a 2nd tier (or outright paid to leave the league) because at some point, the big boys will grow tired of sharing with Purdue and Vanderbilt. Another option would be a tiered revenue sharing model based on each school's revenue generation.
The 2nd tier gets a little fuzzy. How much does revenue decline in this 2nd tier? TV will still want content, but how much will they pay for the 2nd tier? Will alums pony up for this 2nd tier? In the end, I think there is probably further striation and a complete overhaul of Divisions. Some revenue generating sport leagues (P2 above) will probably leave the NCAA, but at some tier, it probably remains inside the NCAA with the other sports.
Lots of variables that are hard to predict, but in 20 years I don't think college sports looks anything like it does today.