I don't think if he stays in Napoli for many weeks because there are some teams that want to hire Osimhen for the net season if they decrease the orice for this player and for some teams like Real Madrid, Osimhen can be a good alternative option.
For Real Madrid getting Osimhen for the asked price by Napoli doesn't make sense at all since they could get Mbappe from PSG for the same price. I even think PSG are ready to sell for any price more than €100m since they will lose him as free agent next season. Osimhen contract will not due soon so Napoli will not reduce their price.