We noted with interest the Upgrade: Travel Better blog response to a reader email on seat assignments. Speaking from our experience, we agree that booking your seats any way but directly with the carrier does not guarantee your seating will be confirmed by them. If your seat request comes back unable to confirm…they won’t usually bother to tell you.
The airline itself has no good excuse to intentionally remove your seat request. Most airlines acknowledge that your seating assignment is not a guarantee(even if you pay a premium to receive it). It may be changed for safety or operational needs. That usually means a schedule change, an equipment change, or special needs(small children, disabled, etc). Exit rows are the best example of a safety need to switch a seat. Lots of people who sit there want the extra leg room, but cannot fulfill the duties of the post…
Upgrade’s advice is good. Stay on top of it. We recommend booking direct, but even if you don’t, book your seats direct. Check periodically, either with an online tool on the carrier’s site if available, or through the call center, to ensure your seating. If you don’t have time for it…and in today’s busy world…who does? Check after every schedule change call/email you get, and at least at the time of booking, one week after booking, and one week before departure.
Good luck though. On a recent reservation on Delta, purchased this summer for travel next month, Delta changed the schedule ten times, and not once did they rebook the seats. Nor will the website let them then be assigned. Also, unless they reissue the ticket(which requires a phone call), a schedule change makes it impossible to check in online or at a kiosk.