They aren't kicking anyone out, at least without a better excuse than, "You don't make us enough money." Maybe, if there were some institutional control issues.
Again, imagine being Rutgers and getting booted out because, "You don't have enough value." Yet Pedo St. is still in the conference and looked upon as a gem. There is no way the Big 10 wouldn't get their asses sued off and lose the lawsuits. There has already been talk of anti-trust if they added more from the PAC, imagine if they started kicking teams out.
As I said in my earlier post, if the top teams decide that they need a power league, with no bottom feeders, they will leave their existing conference and form a super league. It avoids the pitfalls of kicking teams out of an existing conference for no other reason that money.