Airlines can't wait to unblock their middle seats

EXCLUSIVE: Delta internal memo quietly "updates" its safety promise before the holidays

It seems irresponsible to cram passengers into a plane at the height of a dangerous pandemic. But over the weekend, JetBlue said it would return to full capacity on Jan. 8. Alaska Airlines is unblocking its middle seats two days earlier.

Some airlines can't wait. Delta Air Lines, which had promised to block middle seats through Jan. 6, just revised its b…