Kernel updates are xen compatible?

From iWeb.com techs: “…any installed kernel on smart servers must be xen
compatible. It is best not to update smart server kernels and to wait
for a future xen update”

Do webmin kernel updates bear in mind that?
I never have had that kind of problems with kernel updates but seeing that quote it has been doubt me.
My Webmin/Virtualmin was installed from scratch.
Thank you