I'm flying to FL to pick up the Dkids from visitation with their dad - and working in a trip to WDW, of course - so my ex bought my plane tickets. I noticed that Delta had changed my flight time a week or so ago, so I commented on that when talking to my ex on the phone. He replied, "Oh yeah, I got an e-mail about that." Gee, thanks! After reading the OP here, I checked again today and sure enough, the flight times have changed again - strangely, closer to the original times.
Last year NWA changed my flight times so often I did not trust their information until I checked in the day before - and still showed up at the airport early, just in case!