Yes but the problem with your argument is that Napoli now starts doing what they failed doing for the whole season and while it is not impossible that they
could do it, it is more likely that they would not do it. They have a tough schedule and if they now beging to win all their games against the strongest teams of the league, well then it is well deserved. But I doubt that anyone believes they can pull that off. They have never really had a serious winning streak this season and it would come as a big surprise if now the time has come and out of a sudden they can play their best level and maintain that level until the end of the season. They have been playing to erratically until this day and that's the more probable end result for them. They will remain erratic, win some, lose some and finish the season in the midfield somewhere.
The erratic form of Napoli throughout the season does raise doubts about their capability to maintain a high level of play against tough opponents consistently. It's not impossible for Napoli to start winning against strong teams and climb up the ranks, but it does seem more likely that they may continue to struggle with inconsistency. Their lack of a serious winning streak so far contribute to the skepticism surrounding their prospects for the remainder of the season.
It would be well-deserved if Napoli were to start winning consistently, but they need to remain realistic about the challenges they face and the patterns they have exhibited thus far. It wouldn't be surprising if they continued to experience ups and downs and finished the season outside of top four. It's reasonable to expect that they may struggle to maintain a consistent level of play until the end of the season.