Pretty easy to check.. But I can't post travel net screencaps.
Go to Nonrev listings.
Put in city pairs. In my case I put in ORF-NYC for tomorrow.
First flight tomorrow 0610 to LGA has TWO nonrevs listed. You see that by hitting the thing that looks like a paper for STBY LISTING
That makes a popup with NONREV STANDBY LIST come up.
You can see who has listed and what their date of hire and status is.
You can then press VIEW AIRPORT STANDBY LIST and you will see who has already checked in
So yes, I can tell if people are listed, ahead of time, and what status they are.