It is explained in the chapter his one remaining finger doesn't have enough "pull" to attract Sukuna to it and bind his soul there. He's gone gone
The one possibility would have been for the Japanese populace to be so scared of Sukuna that their negative emotions create a Curse based on their fear from him... But that would not be Ryomen Sukuna the character we had but a completely separate entity
Theorically, yes, I guess.
Thouh this isn't your ordinary cursed spirit, but a human who became one.
I could totally see him being reincarnated into Yuji and Nobara's son: Itadori Buji.
First scene of JJK next gen:
-Yuji takes his newborn son Buji into his arms, but the later looks at him with a disgusted face and says: "Don't touch me like that, you brat!"