Really appreciate the response. I wouldn't mind staying in Rome another day since it's the weekend and just need to get home by Sunday, if we can get the hotel and food reimbursed. It's certainly not the worst city to be delayed in. Would Finnair rebook you in business class the next day if your ticket is a reward ticket? That to me is the main concern here.
I have had business class tickets where the upgrade was paid with points and Finnair initially rebooked me into economy. Chat with customer service through the app, and I was upgraded back to business
So if the “auto rebook” would throw you into economy then react immediately and the customer service will fix it