I like WireGuard and wouldn't blink at a client proposing to use it to create a secure network fabric for their deployment environment, but it is not the norm for people to do stuff like this; in K8s land, this is what service meshes like Istio do, and more generally this is what people use overlay networks for. WireGuard could form the basis of an overlay network, if you added the same bells and whistles Nebula has. But I don't think Jason has in his plans to add those bells and whistles himself, because that's not really WireGuard's charter.