cPanel should work on rocky as its supposed to be compatible with CentOS 8 but they did come out and officially support AlmaLinux
Given that Alma was initially founded by cloudlinux that makes sense. So while it should work it will be fully unsupported by cPanel. Looking through their forum they seem pretty committed to alma as well. Seems like plesk may be supporting alma as well as CentminMod.
Its a shame as I am on the rocky linux bandwagon but it seems that many web hosting companies are backing alma out of the gate over rocky.