All of those prior submissions were from user 'dulo'. If you check their history, all 153 submissions of theirs are dead.

This includes submissions from such publications as the Washington Post, USA Today, Popular Science, Fortune, Slate, a whole bunch of newspapers from fairly major cities, and much more. Most of them seem to be reasonable submissions, too.

They were all within about a month or so of each other, starting right after the account was created, and mostly happened in large batches. It seems highly likely they tripped some anti-spam or anti-flooding detector and the user was perma-banned and all their submissions instantly killed.