Releasing Victor Osimhen and having new striker is normal as we are now having new coach at the Napoli after having worst end of the season which bring too much decline in quality and having no consistency after winning title with this all happen due to management level mistake which bring serious trouble and team gone in deep trouble after this all, but now they are working to bring back themselves at the better spot which they deserve in Serie A.
Antonio Conte and Romelu Lukaku have good relationship while these both already work and achieve better results, so things can take good change here as well. Romelu Lukaku is having good depth in last few seasons with he can shine under Conte here at the Napoli which could be good for them because we can expect better results and improved performance which is also important for them for having success.
If Conte do that, he will transform Napoli like Manchester United where the coach kick the players that he don't like including the good ones and replace it with his "golden boys". Ten Hag always sign his players from Ajax or Netherlands, Conte might sign his former Chelsea players.
Finish on rank 10 is quite normal for Napoli, they're a mediocre team, so don't expect too much.