Yes, I agree with Professor Lenard.
I think citizenship revocation is a punishment that really hearkens back to a time that we no longer live in. It really destroys the relation between the individual and the state. If we start by doing that, what other crimes should we start punishing by revoking citizenship? There are numerous heinous crimes that would deserve similar punishment. I think we're entering a very difficult and a very dubious territory. I think my legal colleagues from other universities have spoken to that issue at length.