When you create a new post in the admin WP auto assigns the next available ID to the post, creates an auto draft, etc. There is a placeholder added to the DB.
On the front of the site ACF does not do this. Nothing is created for the post in the database until you hit submit. You could guess at the permalink based on the title being entered, but since there is no post ID yet, yes, anything that requires that post ID is impossible from the beginning
