I wouldn’t worry about it. It was a bipartisan resolution that was passed during Bush’s presidency. The only way i see them re-examining whether to keep the program is in 2032, when people on IBR want forgiveness for the 25 years of payments.
Not sure if you meant they would reconsider IBR for future students in 2032 or they would change theur minds and tell people in 2032 that made 25 years of payments that they were screwed now, but I am sure we will know well in advance if they decide to cut either. It wouldn’t be retroactive. They can’t tell people they have a repayment option and then have it change later. People would have to know in advance that they didn’t have that repayment option. I don’t know if two years from now they will say “no more IBR,” but it wouldn’t be for loans you took out prior to the policy change.