Sasuke only used kirin once, betting on him to use it again is just ridiculous imo. So lets leave that out the situation.
Kimimaro wasn't even using curse mark mode in that scan. So therefore his bones density won't be as strong. If he goes version 2 it's GG Sasukeeee.
Now you said sasuke should be able to cut his bones because he deflected the samurais chakra attacks at the kage summit. But the sharpness of his blades have nothing to do with that.
Kimimaro engages taijutsu against sasuke and brutally murders him until he finishes him off with his bone forest technique.
The bone density doesn't rely on raw power, but his infusing of chakra with calcium, and the KKG's ability to manipulate osteoblasts/osteoplasts.
Their base stats overall are 30.5 for Kimi and 31.5 for Hebi Sasuke... You think Sasuke is just going to stand around and let Kimi cut him up? Don't be so blinded. Even Part 1 Lee engaged Kimi in H2H and he had neither the Sharingan nor Hebi's speed. In the unlikely event that things get too much, he withdraws to mid-range combat.
As I noted earlier, there is a scan somewhere of the average samurai cutting straight through his bones with nothing more than unmanipulated chakra... Chidori Katana is on a whole other level not just because of Sasuke's strength, but because of how concentrated lightning interacts with bones.
The denser Kimi makes his bones, the easier Chidori cuts through because being dielectric, the bones will store the electricity that it comes into contact with, making it easier to slice through. This is because the denser they are, the better an insulator they become, leaving him with concentrated lightning in his bones. It also means Chidori Nagashi will work as a nice primer.
