If the next president reverses the order, then all these people are in the same position and might owe additional interest. Banks know this, so they will hold it against anyone seeking credit. Congress doesn’t even have to vote.

With the income based repayment, they aren’t considered delinquent on their loans, interest doesn’t build, and there is a path towards having the debt forgiven eventually.

You can look up historical interest rates for federal loans. They have never been that high. https://studentaid.gov/understand-aid/types/loans/interest-rates#older-rates