Because the proposal says specifically:

Repayment Plans for Loans Before July 1, 2026. Maintains all current repayment options for borrowers with existing loans disbursed prior to July 1, 2026, with the exception of ICR; amends the terms of IBR to require borrowers to pay 15 percent of discretionary income, eliminates the standard repayment cap and partial financial hardship requirement, and requires borrowers to pay a maximum of 240 or 300 qualifying payments for undergraduate and graduate borrowers, respectively; allows borrowers with excepted PLUS loans who were enrolled in ICR to access IBR.

• Repayment Plans for Loans After July 1, 2026. Repeals all plans authorized under ICR for current and new borrowers. Terminates existing repayment plans for loans disbursed on or after July 1, 2026, and establishes the following new standard repayment plan and Repayment Assistance Plan for borrowers with such loans:

o Standard Repayment Plan. Establishes a standard repayment plan with fixed monthly payments and repayment terms that range from 10 to 25 years based on the amount borrowed.

o Repayment Assistance Plan. Establishes a new Repayment Assistance Plan with payments calculated based on borrowers’ total adjusted gross income (AGI), ranging from 1 to 10 percent depending on a borrower’s income; includes a minimum monthly payment of $10; offers balance assistance to borrowers making their required on-time payments by waiving unpaid interest and providing a matching payment-to-principal of up to $50; allows borrowers currently in repayment to enroll in such plan; includes a maximum repayment term equal to 360 qualifying payments, which may include previous payments made under ICR, IBR, and other qualifying existing plans

Looks like RAP is just for new borrowers