Originally Posted by
FlyNhighAgain
There was a time, before reconfiguration to downsize F, where the 321 and the 757 boarded through 2L.
The 757 isn't near as critical since there's more room between the 2L door and the #1 engine nacelle. After a couple of instances of nacelle damage on the A321 due to contact with the jetway US stopped boarding through 2L on the narrowbodies. As a operational bonus for the 757, that allowed the stop line at the gates to be in the same place for all the narrowbodies.
Jim