One of my biggest problems with the new notepad is you've lost using it as a forgettable scratch space. Anything you put in the new Notepad now gets written to your drive, even if you don't save the file.
You can't type or copy/paste anything sensitive into notepad anymore as a temporary space even if you don't save the file.
There is a setting to start with a fresh window. But rereading the text kinda concerns me. Starting a new session is when the previous one is discarded?