Headquartered in Georgia and therefore the possible boycott target. They're getting ahead of the issue.
Bingo!
There is an element of the Georgia election law issue the Left is fully utilizing. There are a lot of easily excited people in the Atlanta area and thus within Delta's employ. Delta's public reversal is a C-level corporate response equal to big city store-keepers boarding their windows well in advance of riots.
But there is a better explanation, and those who may have missed Soul of the South's #41 upthread would benefit from a quick read. The threat is not just faced by Delta or Atlanta alone, it presents as a rapidly growing problem currently facing our entire nation.