I have received these type of emails as well from BA, after I have been on one of my bookings, even if I hadn’t changed anything (seats as an example) and the email never indicated what was changed, just that the change had been made. Very odd. That said, I checked my LH booking for later in December only to find out my seats had been moved from the Upper Deck to lower deck, and never received notification of the change from LH. I called them and they said they do not send such notifications as aircraft changes can happen? Luckily I could re-allocate my seats back to the upper deck, but this somehow makes me prefer BA’s approach as any change to your booking either by yourself or by BA, you get notified.