On June 1st, I flew from Boston to San Francisco. My flight left Boston just before 11 AM. Thanks to in-flight wifi, more than five hours after departure (and with less than an hour before landing) I got this gate change update from JetBlue:

I had cellular data and wifi up until I boarded my flight (at Gate C19), so it seems unlikely this was delayed. As best as I can tell, either someone or some automated system sent this hours after it was relevant, for reasons I can’t fathom.