Victor Osimhen is an important figure behind Napoli's success in winning Serie A. I am far more certain that the club will try to keep Osimhen at the club despite receive offers of up to hundreds of millions from outside teams who want Osimhen. Even if he want to try playing in the EPL, I'm not sure Osimhen will agree with Chelsea
I think he will stay for Napoli next season because indeed he was an important factor in Napoli winning the league last season, but Min-jae Kim's departure to Bayern Munich will also make Napoli's defense less good because so far Min-jae Kim playing well at the back, I think even that will cost Napoli a big loss selling Min-jae Kim.
If Victor Osimhen also leaves, of course Napoli will lose the opportunity to compete in next season's matches which I think will be full of tough competition, especially since many clubs are shopping for the best players to compete in next season. Napoli, of course, must get new players to fill in several lines to strengthening Napoli next season and being able to defend their championship title.