Had a IAD-CDG-DEL flight booked for April with a confirmed GUC upgrade that was applied last month before the rules changed. AF cancelled one of my flights & put me on their next available flight a day later. I called to move back to my original date of travel & was told that there were no AF flights on that day so I would have to switch to either KLM or VS. There was no upgrade availability on KLM & if I wanted to apply a GUC on the VS flight then I would be bound by the new rules. I explained I was not looking to book a new ticket but just wanted to travel on the date I had originally booked. I was put on hold a number of times while the agent checked with a supervisor & after about an hour he was finally able to switch me to Upper Class on a VS flight.