Notepad in Windows 11 now has the option to "Open content from the previous session"
If your settings are as above, any tabs open when you close Notepad will be restored when you next run Notepad. Each tab is saved to a file in:
%localappdata%\Packages\Microsoft.WindowsNotepad_8wekyb3d8bbwe\LocalState\TabState
The files contain the original location of the file plus its content. If the file has been deleted from the original location and you close its corresponding tab, you'll get a dialog popping up asking if you want to save changes to "the file". Selecting yes will save a copy of the file (or try to) to its original location.