Hello Alex,
Thank you for reaching out! KernelCare goal is to avoid the reboot right after the kernel update but keep the kernel secured.
It is good to keep the packages up to date and update packages as always (‘yum update’, ‘upcp’ etc.)
Also, you don’t have to, but you should update kernel (so that next reboot due to hardware/whatever, you are booted into a new kernel). There is no need to reboot -- and that is the goal of KernelCare.
On cPanel systems you can configure automatic updates here:
https://documentation.cpanel.net/display/68Docs/Update+Preferences
With KernelCare+, which is in beta now, you'll be able to patch also OpenSSL and Glibc without a reboot, stay tuned.
Please let us know if you have any questions. Thanks in advance!

sorry, my question was not clear, Will I have to reboot the server after CPanel update?

Thanks for continuing! If you don't need to boot with the new kernel, then a reboot is not required.