Microsoft is changing the way you sign in – and it could be a security nightmare – ZDnet
Avoid staying signed in on a public computer – Microsoft
The web browser sign-in experience is changing when you sign in to any product or service using your Microsoft account. Starting in February 2025, you will stay signed in automatically unless you sign out or use private browsing.
If you sign in on your own computer, your browser will remember your sign-in information, but if you sign in on a computer, phone or tablet that doesn’t belong to you, or is accessed by other people, you should follow the steps below to use a private browsing window instead.
Seems to me this is an extremely bad idea!