I checked in right at 24 hours before the flight. I was given a window seat in the very back of the plane, not my preferred aisle seat. I wasn't overjoyed, but as long as I didn't get a middle, I could handle it. The plane was sold out, but checking in as early as possible shoul have made it possible to get my preference. I am not sure what to make of this; why have a seat preference option on the My Profile page if it's not going to be honored?
I am happy that being Elite will alleviate this situation for 2019, but for all of the non-Elites who have checked off a seat preference, this is unfortunate. I hope this was just a hiccup, and that seat preferences will be honored going forward for everyone who has bothered to list one.