First thing first, please take this with a grain of salt, I am not promising anything. There are many rumors spreading around that Rockstar wanted Sony to delay their conference by 5+ hours, but Sony could not accommodate Rrequest. According to a post on the GTA forum, the reason behind the possible delay is that R trailer for RDR involved an outlaw entering a saloon and shooting many innocent people, this would be a PR nightmare (and in bad taste) due to the recent events that occurred this past weekend in Orlando, FL (link to forum page account name: jedijosh920 )
This cause Sony to reveal the Days Gone gameplay reveal as the finale rather than after the trailer (which seemed out of place). My speculation is that Sony needed a filler to replace what would have been a controversial ending (again due to the tragic events that occurred this past weekend). Again this is all speculation, but we may have a reveal of RDR tomorrow.