I have a bold prediction that Napoli next season won't even be in Top 4. I expect them to lose a lot of points in begining of the season. Everyone will play with more fire against them since they are champions and with possible departures of key players I see that happening.
I know where you're coming from from and I understand it. After the season inter Milan won the league, they were not that good anymore, same with AC Milan the season after the won the league so it won't be a big surprise if same thing happens to Napoli.
Despite all these, a part of believe Napoli won't be like that next season. They might learn from the others and make amends.
Osimhen looks like the only player that is on his way out and even him is not certain. The rest like Kwara are not going anywhere and they also have more money now to make more signings. They might not be the best next season, but they be in the top four.