I do not disagree, I’m just curious what ideas are out there to manage the unintended consequences.

I'm glad you don't disagree, but that makes it confusing that you started your response with "I don't think that's correct"

I agree that's the theory, I disagree that it actually is what would happen in practice. E.g., if the government stops guaranteeing the loans I seriously doubt banks will accept "future earning potential" as collateral. So I disagree that it's actually collateral (your initial claim). The real collateral is the govt promise to back up the loan.

So the question still stands: if the government no longer guarantees the loans, what is the proposed solution to prevent banks from no longer lending to students?