No - the article contradicts itself. The author says it's "a myth" and "just set up spf/dkim", and then later says "This is already happening with one specifically requiring mails to be sent from another Big Mailer Corp to hit the inbox, or requiring that senders be added to the contacts for others. Any other sender will hit spambox unconditionnally for a while before being eventually upgraded to inbox."

Which is it? Those of us who have run mail servers know that you get unconditionally spammed all the time.