It depends on the loan. Lower rates will make little or no difference for someone who elected to pay only the interest or less (Negative Amortization) once they have to start paying down principal.
Going from an I/O teaser rate of 1% to even 5% is going to hurt these people.
The only thing that would help is if rates are in fact lower than 5 years ago and they refi into the same loan.
Anyone forced to start paying down principal will be facing a higher payment.
