Need some help from the experts on this forum.

Currently have a flight ZRH to IAD to PHX, party of 2 and we are ticketed in Premium Economy (R). We show as #5 and #6 on the upgrade list to Polaris.

Based on some flight checking using the Flight Status tool, I knew there were many free seats on the ZRH to ORD flight for the same day we are currently traveling and when I checked it today via expert mode I get:

• J9
• JN9
• C9
• D9
• Z9
• ZN9
• P9
• PN7
• PZ7

However, when I check the full routing ZRH to ORD to PHX it shows:

• J3
• JN3
• C3
• D3
• Z3
• ZN3
• P3
• PN0
• PZ0

And the same above numbers for the connecting flight.

My question, can I change my flight to the new routing (ual.com actually will give me a travel credit to do this booking into S bucket), then apply the PlusPoints (I know it will take more PlusPoints since we would not be in Premium Economy) and the upgrade will be confirmed then and there? Or are the segments married in such a way that the Polaris portion won't clear immediately and I will stay on the waitlist until closer to departure?

Thank you for anyone who can provide some advice or learned knowledge on this.