Osimhen's price is too high for a team like Ac Milan I don't know where the idea comes from to say Ac Milan trying to hire Osimhen for the next season but as far as I know, other teams in Serie A can't have enough money to hire this player for the next season and even if Napoli gets some offer for Osimhen from other teams, there will other teams like PSG with better financial situation.
But regardless of that, I think Napoli's first priority is to keep Osimhen for another season.
Ac milan is not really interested in recruiting Osimhen there is not even an issue linking them if they want to recruit osimhen in this transfer window. I agree with you that the high price of Osimhen will make the Serie A team unable to bring in Osimhen in this transfer market. For now only the teams from the Saudi Arabian League have strong finances to recruit Osimhen from Napoli.
For now Al hilal is trying to seduce Osimhen in this transfer window where Al hilal has made a bid of 140 million Euros to bring Osimhen from Napoli. So, if Napoli accepts this offer, it is very likely that Osimhen will play in the Saudi Arabian league next season. But i think he will consider accepting the offer from Al Hilal because he is still quite young and can pursue his dream in europe with another team like PSG.