Hm, that would be the ideal situation, but a wiki-style ability to create new notes while writing would probably be sufficient. Sort of like @trebso suggests, but more on the fly even.
Let’s say I am writing meeting notes and a new topic comes up that will require a separate note – it would be great to be able to create that note on the fly without having to leave the original note, just by putting markdown around the topic, sort of like in wikimedia: [[new note on something that comes to my mind]].
Or I am writing to prepare a class session (I teach) and I would like to create separate notes for each required reading so I can quickly refer to it during the session.
Or I am writing a journal entry for the day and ideas come up for projects or readings to take notes on.
In these scenarios it would be less important to be able to parse the text - title and body of note - than to be able to continue writing. Copying any body text for the new note and going to it with a click would not be so much additional effort.
If the markdown is not workable, adding the option “new note in [default project]” to the “link to” contextual menu item would also work – not quite as quick, but helpful already.