In many cases systems run out-of-tree drivers like Lustre, MOFED, NVIDIA etc. that tend to break due to kernel internal API changes. Yes, also for changes incorporated into minor RHEL releases like X.Y -> X.(Y+1), though not for kernel security updates within a minor X.Y release. At the same time they might need to keep up to date wrt security updates. So if CentOS stream implies that the kernel will randomly get an API-breaking update, with no security support for the previous version, that is not workable.