Wirelessly posted (BlackBerry9630/5.0.0.591 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/105)
As of today upgrade reciprocity went into effect but it is only at the airport, not in advance. Betting on that being successful for securing an upgrade is a bad idea IMO.
You can put your CO number in and change it after the upgrade clears. Many folks have reported success with doing such so long as a person isn't involved (i.e. do it at a kiosk or during OLCI). If a human gets involved they might just bounce you from the upgrade since that is technically what the rules say should happen.