PSG does need new players to replace Mbappe but they don't have to get players who have equivalent performance to Mbappe.
Now we can see that PSG doesn't have any problems winning the league 1 title even without Mbappe, PSG will still dominate league 1 just with the existing players and that's all because the players that PSG has are of higher quality compared to other teams.
Bringing in Rashford or Osimhen will not be that easy when Napoli and Manchester United are both in bad shape and need help from these reliable players to get good results in the next season.
I think PSG will not be able to get Rashford or Osimhen this season or may have other alternatives.
The Champions League is actually PSG top priority so far when recruiting the world's best players, but unfortunately every season they continue to fail and maybe even this season their fate will not be much different from the previous season, if indeed they only focus on Ligue 1 of course PSG management will not continue to spend large funds every season to strengthen the PSG squad, Because without the best players in the squad, of course they still have the quality of players far above other teams in Ligue 1.
Osimhen and Rashford are indeed rumored to be targets for PSG for replace Mbappe in the front line, but so far I don't think they have made a significant approach to bring in these two players except only rumours that continue to circulate without any official confirmation from PSG, regardless of whether all these rumors are true or not, but I think both players will suit PSG's style of play which has often counterattacked fast from both wings, besides that Osimhen who has ever played in Ligue 1 so far will certainly have no difficulty adapting to the atmosphere of Ligue 1 so I think he will quickly integrate into PSG game later.