Some of the mechanical and other issues in ATL are being blamed on the increased variety of equipment. This causes pilot and maint issues that are greater than normal... and normal is not always smooth. I got this info direct from Delta people who I know personally... my Diamondness does not work on them as they knew me when...

They did not have any answer for the gate issues other than saying they are trying to pack 100 gallons of (dookie) in a 5 gallon bucket....