OSX: Spotlight shows the content of locked notes
You need to close your notes



I justed tested this in OS 10.11.5 and the contents of the note don't show, just the title.

I created a note and titled it for which it would be easy for Spotlight to find:  "Smattering test note"  (I have no other instance of "Smattering" on my system).  Here is what it looks like after I have locked and closed the note.



Doing a Spotlight search for "Smattering" yields this result:



It autocompletes the note title (ligher grey text) and clicking on it opens the Notes App.  Until I unlock the note with my password, the contents are not visible.

If I don't lock and close my notes, if I do a Spotlight search, the contents will be visible