Lesson learned for me - Always set up equipment change alert
My wife casually mentioned to me that her SEA-CDG flight next month had a new seat assignment. So I took a look and sure enough, original 5A assignment had been moved to 8A due to equipment change (I forget but possibly from 767 to a 330, so the herringbone should be an upgrade).
Just a lesson learned for me. I already have ExpertFlyer so I set up equipment change alerts for all future flights and will continue with that. I also set up a seat alert for my wife in case another window seat should open up closer to the front.