Hello Shar533,
how do you know your interview was waived? Do you know if interview comes only before Medical Request, if MR has come, there is no possibility of interview request after that?
if Medical and RPRF come togather then your interview is waived, mostly 85% CHC sends Medical and RPRF togather, but if VO required or have doubt then VO call for interview that's the rare chances juts I rate 5% chances from all CHC's.
remember Buffalo NY send medical request first and then RPRF, so keep in mind if you are Buffalo applicant then your interview will possible even after medical request, but once RPRF issued then understand that 98% to 100% your interview is waived, so you know your documents and your file status are good enough and VO is satisfied so, even you can say that 100% your interview waived off.