My experience: Yesterday I booked United award travel on AC YOW to YLW-Kelowna via YVR. I was able to select seats on the AC website. I selected “My bookings” on AC using the “Air CanadaConfirmation number” that shows up in United’s “Manage Booking”.

AC seats are able to be selected once My Booking opens up through “change seats”. Even though the booking is in Economy Standard with AC, I selected the front rows going and a combination of front/exit rows on the return. These seats are labelled Preferred for up to $65/68 each. There was no attempt to charge for the seats. I checked today, all seats have stuck to the reservation and shows up on United as well. Also, I picked a D and F seats, they stuck to the reservation as well.

Checked luggage - Nothing changed here, I still get 1 bag as a Star Alliance gold, the wife as silver gets nothing as does daughter with no status.