Several airlines are doing this more and more proactively, they say it’s to “improve” customer service by rebooking you automatically and not making you rush… I had a similar incident a few years ago on Delta where my inbound was slightly delayed but parked right next to my connecting flight… went to that gate, a full 30 minutes before boarding, and saw that I had been rebooked 7 hours later. Took the gate agent a whole 30 minutes to get me moved back to the original flight, the comment was that this proactive rebooking was causing more problems than it was solving. Technology is great, til it’s not.