While checking just to be safe is never a bad idea BA use a specific header for seat changes as per examples given. ( made some omissions for security's sake but refer to the red lines against emails on the far right of the picture).

They do seem on a roll email wise at the moment. I have emails telling me about some of my upcoming trips & how to prepare for them one of which is in November & one over new years( although not for some others in between now and then) which imo is totally useless this far out although I also dont feel the need for them but I guess they're generic and sent to all no matter how often you fly.