I think if you look at the corporate media polls, Trump does better with polling from Registered Voter surveys than likely voters, based on their likely voter criteria. What they are saying is supposedly the electorate changed their mind and Clinton now will have the motivated “likely voters”. I doubt that..how can a motivated voter for Trump flip 180 to be motivated for Hillary. I think its more plausible they change their criteria, or just plain throwing the criteria out the window like here.
Likely voter is a screen to exclude deplorables. In this election, registered voter is more reliable.