I also think Napoli has plan for Osimhen transfer if they sign Lukaku from Chelsea. Osimhen will probably leave Napoli and join another team like PSG Arsenal or Chelsea. Lukaku will fit in well with Conte team because they worked together before. But this transfer is taking too long and it is hurting Napoli season. Osimhen will likely leave Napoli soon and they won't stop him. If he does not get hurt Osimhen can score a lot of goals this season. He will probably choose team that plays in Champions League and has good chance of winning titles so Chelsea might not be his top choice.
This is not about Osimhen picking the club he wants most to continue his career but about the price tag on his name that is making it difficult for most of this top teams not to sign him. Some have showed interest in the pay like PSG and also a rumor from Arsenal but they’ve all backed out from it because of the price. Another thing is that, his performance last season was not encouraging and not what is worth been paid that price for, but since Napoli is just after the money they’ll get from the transfer, they don’t look into all that. If he’s going to join a club that plays in the champions league then it’s definitely not Chelsea and if not Chelsea, which other club can he go to and are willing to sign him with this price and also playing in the champions league? Is there any at all? I don’t think so for now.