OIM's pretty clear
The applicable block of R-days, standby(s),
or standby trip(s) shall be dropped.

If the pilot provides less than 72 hours notification, the drop may be processed at the Company’s discretion.

Q&A not all that helpful, but A9 clearly say "The applicable R-day block will be dropped"....then gets wishy washy talking about what Might happen.

One darn thing I'm certain on...is what Might happen ain't gonna happen in any seat that's not short on pilots