Originally Posted by
dvo1029
I think United should not send a message like this unless factual and they should merely state the facts that immigration lines are very long and you should arrive 3-4 hours early and if not at the gate 15-20 mins before flight time you will not be able to board.
Maybe they are going to start enforcing it soon, as valuable time was being wasted on identifying and removing luggage (and re-doing the upgrade list). If you don't meet the deadline, then they can start offloading your bags and reduce delay in departure.