I think there is another reason why Napoli's president fired Spalletti after he won the Italy Serie A title for Napoli; it was not Spalletti's fault that Napoli was knocked out of the UEFA Champions League competition. Napoli was knocked out because Osimhen was not 100% fit to play for his club when he was needed most, and Napoli was knocked out. I believe Conte will not allow Osimhen to leave Napoli for any other club because he knows what he can achieve at Napoli if Osimhen remains at Napoli. Conte will need to strengthen his mild field and defense so that he can use his favorite formation without finding it hard to win matches when the Serie A league season starts.
Spalletti dismissal is the beginning of Napoli destruction this season, we can see how Napoli performance was destroyed and even 3 times the change of coach was actually unable to lift Napoli performance this season, the bad relationship between Spalletti and De Laurentiis is the reason why Spalletti left Napoli after winning the Scudetto last season, De Laurentiis is the owner of Napoli who often interferes with all coaching methods and the Napoli squad so that indeed Making Spalletti uncomfortable at that time because he did not get the freedom to determine Napoli main squad, that's why currently Conte gave a written condition to Napoli that there should be no interference from De Laurentiis in determining the squad built by Conte when coaching Napoli.
Currently Conte has officially coached Napoli and reportedly Napoli has asked for several names of players who must be recruited by Napoli in the summer transfer including Lukaku, the arrival of Lukaku who is indeed Conte priority will certainly make Osimhen's position as a striker may be threatened, but I think when Osimhen is able to maintain his performance at Napoli of course he will still be able to get a place in the first squad, But isn't it reported that Osimhen is now a player that Napoli will sell to another team?
I knew there was something else that caused Spalletti's dismissal as Napoli's head coach. If the Napoli owner always wants to decide how Napoli players will be used, he will make the club not to move forward because no good coach will last as long as the Napoli head coach can't decide which player is okay for him to use in a match. For Conte to identify Lukaka as the number 9, he wants to secure his signature for Napoli, which means that Osimhen can't fit in with his playing style. Osimhen might not have much playing time under Conte, so there's a need for him to push for a deal with another club where he will be the number-one striker.