I don't think Napoli are ready to lose their keyman to any elite club this summer, they've solid plans for the Nigeria international and keeping him would be their absolute decision.
You may be right because we have not really heard anything in regards to that case about the Nigerian player in Napoli, perhaps it could be that Napoli has realized that the player still have a lot of things to offer them if they decide to keep him, well considering the condition of the transfer market were every club is currently trying every means possible to make there club strong no club will like to sell there player that's still very active on there front line, so I agree with you because with the look of things I don't think he will be leaving Napoli this season maybe if they are to sell him it will be after this upcoming season because the competition is too much on this season.
Maybe he might want to work with Antonio Conte. Conte may have convinced him. If Osimhen is in an important place in the coach's plans, he may have wanted to stay in the team. Napoli is a strong team and they will compete for the championship this year too. Kvaratshkelia was going to stay in the team anyway. If they get Lukaku and Osimhen stays in the team, they will have the most dangerous offensive line in the Italian league.