A shout out to Kelly Amott for bringing this to resolution. I’ve always wondered what the difference between the the requisition reopen and reactivate operations and there’s not a bunch in the documentation that I’ve seen that would explain it. He got the answer from a case and was kind enough to share.
Update and FYI – To take the req off hold I was using the Requisition – reopen spec. Oracle advised that reopen is for cancelled reqs. The specification I needed to be using is the Requisition – reactivate.