Project folders contain notes belonging to, or originating in a project. Meeting notes are in the project (or area) folder the meeting was for.

From meeting notes actions may follow, which end up in the project’s todo-list.
From meeting notes ideas or associations may originate which can turn into a Note, Notion, or one for the Idea list (if it is something that seems like it can be put to action more or less quickly).
In meeting notes there may be little pieces of knowledge or examples mentioned by other participants, which can turn into Notes, or I can add as example to an existing Note. Such a Note, especially if it starts as stub, might be ‘upgraded’ to a Notion at some point in the future.
Meeting notes may point to existing Notes (pointing to examples, or arguments) or Notions (a concept)

After a meeting I go through the notes to clean them up, and lift things out that belong in other notes, action lists etc.