I also think that Osimhen doesn't need to be thrown away by Napoli if Napoli's own determination is to get better performance next season even though their intention to bring Lukaku into the Napoli team wouldn't be bad either. However, if Napoli can have more classy players like the two of them, why don't they immediately bring in Lukaku and keep Osimhen so that the strength of the Napoli team itself can be more capable next season and have the potential to compete at the top of the standings.
Osimhen has made a lot of contributions to Napoli in the last few seasons, his duet with Kvaratskhelia has been a quite dangerous duet and is even included as one of the best duets in Serie A in the last few seasons, maybe we all think keep osimhen of course a must the right option for Conte, but Conte of course knows better about the players he really wants to be in his main line-up next season, Since being linked with PSG, Osimhen has stated that he wants to join PSG, so that is does raise a few question about his loyalty to Napoli all this time even though he had just extended his contract with Napoli at that time.
I think maybe at this time the loyalty that Osimhen has towards Napoli is one of the reasons why Napoli wants to sell him Apart from needing money to buy Lukaku from Chelsea, Conte very know about Lukaku qualities that he might prefer Lukaku as his target man in next season compared from Osimhen, Osimhen and Lukaku have the same position in playing so it will be difficult for Conte to choose one of the two as the main striker, besides that of course there will be a split in the attack line if Conte prioritizes one of them because of their status as star players in team.