Earlier quoted context omitted.
That's a different issue. You're usually not notified of spam designations, but bounces (where the mail server completely refuses to accept your email) do usually receive a notification. If you're designated as both (for example if you keep sending email that bounces) you'll get blackholed and wont receive any bounce notification either.
An advantage of landing in spam is that the user still has a choice and is in control. Rejecting outright is a "lalalala I can't hear youu!!" type of stupid situation that only big providers can get away with, without the users realizing their bigcorp is the one with delivery issues
Besides, for something truly important, the people or organisations who need to reach me know how to do so other than via email (phone, chat, postal mail...).