AMC has removed the 3 hours, 2 minute run time from their website:
Those people who obsess over a movie run time may want to take a look at what AMC Theaters has just posted on their website. Previously, Avengers: Endgame didn’t have a run time or the official synopsis listed, but that changed this morning.
Today AMC Theaters has updated their website to not only list the official synopsis for Avengers: Endgame, but they list the run time as 3 hours, 2 minutes. The “Extra” name is a placeholder they’re using to hide Avengers: Endgame from website searches:
Now, this could just be a placeholder. If you remember, Captain Marvel showed a different run time when tickets went on sale, and then right before release it as updated to a shorter time. We’ll have to wait and see if this 3 hour, 2 minute run time sticks.