Additional notes and annotations still work the same way, just that now they are called Responses and are displayed in your profile.
Authors can still annotate their own stories, and surface others notes by recommending them (previously they had to approve them, so it’s still the same).
If someone intends to write a private note only for the author to see, now they can control that with a “Private Note” instead of a “Quote Response”.
Mind that both “Private Notes” and “Quote Responses” still appear in context and can refer to a whole paragraph as well as to a specific sentence or word.
PS: I don’t work for Medium