For what it's worth, I had a similar issue yesterday morning (Sunday) when I was booking a flight. There was no MQM/miles/MQD information displayed where it usually is on the payment page. I thought that looked odd and I wanted to compare mileage on a couple of alternative routes, so I switched from the main Delta.com website to the mobile website and everything looked as expected with the MQMs etc. displayed in the usual manner. However, as of late last night everything on the main website seemed to be back to normal with the mileage information available, so there must have been a temporary glitch.