It looks like Napoli are likely to keep many of their talented important players in the team this summer. There is still no offer for Kvaratskhelia and Osimhen as far as I have seen. Kvaratskhelia's market value is much lower than Osimhen but it is still 85 million euros. Not many teams would be keen on signing him both players right away. Especially Osimhen's departure is much less likely because the teams interested have to pay at least 130 million euros for his fee.
Kvaratskhelia's contract is until 2027 so there is no problem about keeping him for a long time. But Osimhen's is ending in 2 years. He might leave for free if Napoli wait for that long. I assume he wouldn't like to end his career at Napoli.
The transfer window has a long way to go until it closes, so we can't assume Napoli will or can keep hold of key players. After all, when the transfer window is about to close there will usually be a lot of transfers going on, so for now I think it's normal for them not to be too hasty. Because it's possible, they still don't share actual information, because it seems impossible for players who have had a big impact in the previous season not to be in demand by other big clubs.