He'll still be a top youtuber even if he deleted his channel and started fresh with 5mil subs. I mean let's look at social blade in terms of subs. #1-#10 (pewdiepie, YouTube "Movies", HolaSoyGerman (Spanish gamer? Or something...idk), JustinBieberVEVO, YouTube Spotlight, RihannaVEVO, Smosh, elrubiusOMG (another Spanish tuber), 1DVevo and Taylor SwiftVEVO)
Now those are the top 10subbed channels, not counting the music ones and the Spanish ones ( no offense ), the options are Pewdiepie or Smosh.... lol for the face of YT. Neither are great but eh pewds is still better. Going down the list you can find better suited candidates like nigahiga, but who are we to pick who YT uses as their poster boy.
At the end of the day, nothing will change for us by him going on a new channel, for him he won't lose money in fact he'll likely make more because once word spreads that the king of YT deleted his channel the masses will flock to his new channel and videos.
Yesterday IGN had a livestream with pewdiepie's sub counter "pewdie-bye" they called it. So yeah. from a business perspective what he's doing is incredibly clever. Still he can chicken out and all this is mere hypothesizing.