30 years of their home name Office brand, known by pretty much every person that's ever had a computer let's get rid of that, and make the unreliable bullshit generator the main brand instead certainly a courageous decision
My take is that Microsoft assumed that everyone is calling it Microsoft 365, which they don't.
30 years of owning the term "Office", having almost every single person who ever touched a computer know that Office is the Microsoft office productivity suite, then deciding that a sort of working, but yet to be 100% defined LLM is more important. The fact that no one stopped this or that shareholders aren't pissed tells you something about how absolutely broken modern computing is.