I am not sure if this is the right place to post (or if someone posted this). I Marlene King posted that the Patsy Cline song Walkin' after midnight contains many clues for the rest of season 5 and were it will be going in season 6.
I thought ending was poor Ali. I wondered if the message at the end was done by another "A" and Ali was a red herring in that moment. (Not sure if this needs to be in a spoiler tag....