this has nothing to do with rust, kernel regulary ships rather experiemental features in some of the releases, there is a reason why only specific kernel versions become LTS
userspace doesn't get broken, you just kernel panic or experience severe slowdown due to some bug (like the one that existed on 6.18 and was fixed in 6.18.1 - not sure what the exact bug was, but updating to 6.18.1 made it go away.