Hi everyone,
I booked a premium fare for LAX-YYC-YHZ but there were some changes to my itinerary and when I use the rebooking tool the only same-day option are flights on Delta connecting to westjet.

When I went to select that flight as my new flight, it wouldn't let me select seats on Delta. So I'm not clear if I'd be sitting in economy? Or first class? Obviously I only want to switch to this flight if I'm remaining in a premium cabin. If by changing to the delta flights I'll be put in economy then I don't want to make the change. It isn't clear anywhere in the rebooking tool what class of service I'll receive on Delta. Obviously Delta doesn't offer premium, but only economy, comfort plus and first class.

Any ideas?