[Stratoscope]

I suppose it depends on whether I'm wearing my "user hat" or my "Notepad developer hat".

As a Notepad developer, I might agree with you that Unix line ending support is a new feature.

As a user, I double-click a text file and it opens in Notepad. It opens fine in all of my other editors, but is garbled in Notepad. That feels like a bug.

I don't try to open .xlsx files in Notepad, so it isn't very relevant to me as a user that Notepad won't open them. If I did open one accidentally, I'd think "D'oh! That's not a text file!"

But this is just terminology. Files that Notepad couldn't open usefully before will now work. That's a good thing, whatever we call it.