Seems like a badly run company.
(Insert that caricature of the MSFT org chart with guns pointing in all directions.)
This seems logical, you don’t want your service to get a bad rep because some internal division marketing team goes dumb. Also, security in case individuals get hacked.
I get legitimate transactional emails intended for someone else and those senders refuse to stop them because I'm not their customer and only their customer can request account updates. Those get marked as spam.