Secure Encrypted Virtualisation uses SEM, but it is not a newer version of it. SEV allows someone to run encrypted VMs that not even the host can read the memory, by leveraging per VMs keys in the AMD PSP that encrypt the VMs pages using SEM.

It would be interesting to leverage SEM to run a version of qubes where not only are the VMs isolated by the Xen hypervisor but are also separately encrypted using the PSP.