Allegri is a genius coach, he can turn a Milan full of old players into Serie A champions, while the current Juventus players, are still much better with Milan's conditions at that time. So, I think, even without Ronaldo, and Pogba's plan to Juventus didn't happen, with Allegri's ability as a coach, I think they still deserve to be favorites to win. It is true that it will be more difficult, but at least Juventus still benefits from the condition of their competitors such as Inter, Milan, Lazio which are in less than optimal conditions as well. Against Napoli, because this is a game that the team need to adapt without Ronaldo, holding Napoli with draw is not bad result IMO.
If Juventus' poor performance in the last 2 match was caused by losing Ronaldo, then Juventus really made a big mistake. It is never good to always depend on one player even if it is a star player. Actually, Juventus still has quite a lot of reliable players in every game, but it seems that some players have lost their enthusiasm whether it's because of Ronaldo or other reasons. Allegri will be responsible for maximizing the potential of his players in the games to come, they will soon get up and get back on the winning track.