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.
Based on what do you make predictions that Napoli will not be in the top four next season? To defend the championship I agree that Napoli will struggle a bit, but to enter the top four I think Napoli is still possible and still has enough potential big. We need to see what the composition of players and coaches will be like next season and if Spalletti decides to leave then things will be much more difficult, because the new coach will have to integrate the existing players with his format and formation scheme.
Likewise with Victor Osimhen, who is currently rumored to be moving, so Napoli must find a suitable striker as a replacement next season. To predict how Napoli will be strong next season, you need to look first at the coach and the new players they bought, so that their strength will be seen next season whether or not they can compete.