This is critical.
As mentioned above, it’s extremely common to have a meeting that might cover topics spanning multiple notes. The only way to handle that using the current limitations is to cut and paste each of those notes (which likely must remain where they are) into a single new note and link that newly created note to the event.
This is a very bad idea because now you have the same data in two places and updates might get made to one place and not the other—and could lead to the very same tangled mess of random snippets of text that we are trying to avoid by using a note-taking app like this.
I’d love to see the ability to link multiple notes to a single event and then the ability to either view a popup menu of the linked notes (when clicking on the notes link on the related/calendar section) or, worst case scenario, at least cycle through those linked notes.