Well it's interesting and adds some context to Kenjaku/Sukuna's relationship.
We first have Kenjaku telling Kashimo that the strongest sorcerer he knew is Sukuna and he made a deal with Kashimo ( & other sorcerers as well ) to incarnate them in future in the hope of fighting Sukuna( at least that's what the incarnated sorcerers seem to be wanting )
So this implied that he knew Sukuna was gonna incarnate again in this period of time and it was also safe to assume they had a deal ?
This chapter seem to be making it quite clear that this is likely the case.
Kenjaku said to the curses that to achieve their goal they had to do 2 things.
1) Get rid of Gojo
2) Get Itadori and Sukuna on their side
It's weird that he said Itadori and Sukuna, he could have just said Sukuna and make the goal to somehow force Itadori into a binding vow ( which he probably could have done this himself if he wanted to )
And then ofc after he got rid of Gojo he said that it's not really important if Sukuna actually joins the party, he can just stay inside Itadori as a vessel his CE will do the rest.
If Yuji from the Heian era it would mean he's different than just " mixing the perfect genes for the perfect vessel " cuz we know Kenjaku had to prepare the bodies of someone for Kashimo etc for them to incarnate ( probably when he casted Idle transfiguration ?
He said he casted it on non-sorcerers whom he had markedd and gave them strength as vessels ) but the process for Sukuna was clearly different, and maybe for a reason ?
Sukuna seem to be aware of that not only bc of the phrase " right the brat is from that time " but also bc he said " Kenjaku goes the grossest things " and it's not like he doesn't know what a vessel is, he knows Yuji is a different kind of product it could be that he's Sukuna's " original " body, maybe an attempt of cloning ? But then he rewrote his genetis somehow...i feel like we need some more infos here
Another cool thing is that he said it like it's normal from people from the heian era to be so tough xD
Gojo playing on easy mode here!