If there are upgrade seats available on the flight/s, which we can determine by looking at availability in certain fare buckets (e.g. 'U' class for business on QF), then if the booking is ticketed
before you put in the request, then it should confirm for the flight/s where that is the case, right away after requesting. Did you want to share the flight numbers and dates and I can check?
This is the thread for checking availability / chances:
Flight Availability/Loadings & Upgrade Probability Help Desk
Cheers,
Matt.