In case it isn't obvious, I'll add that a lot of these gate issues are due to inbound flights arriving to their gates being occupied because of cancelled outbound flights.

There was a Delta/SkyWest flight from SEA that landed at ~11p last night and only managed to get a gate about 5 hours later in the A-pier when WS moved an aircraft to the parking area past E-pier. Very intrigued how they managed to get those passengers to immigration.