Notepad on Windows 11 uses RichEdit https://devblogs.microsoft.com/math-in-office/windows-11-notepad/
I think you may be getting confused with Rich Text Format and the like - I.e. A format/markup and editors supporting bold, italiic, different fonts etc.
That’s not RichEdit - it is a basically a type of text entry box in Windows and the features it can support. The current version of it supports emoji, multilevel undo, auto rendering URLs, drag and drop etc. It’s still just a text box but just a bit more integrated and sophisticated than the older versions.
So Notepad in Windows 11 is a bit more sophisticated in terms of the text interface for users than it used to be but it’s still just working with txt files.
It’s not like wordpad, which could work with proper markup and other formats. This is cruedly more in the realm like notepad++ - working with txt files but with more sophisticated control and options for the user (but to be clear notepad++ remains way more sophisticated than win 11 notepad).
Edit: and of course, the AI stuff is all bullshit. Fucking Microsoft.
So Notepad in Windows 11 is a bit more sophisticated in terms of the text interface for users than it used to be but it’s still just working with txt files.
And, I assume, it will still fuck up file names every single time, complain about insufficient permissions and make us save the zabbix.conf.txt (or whatever non .txt extension file you happened to edit) on to the desktop before renaming and moving it to proper location, right?