I understand your suggestion. Although I am not the administrator of the WireGuard website. But personally I don't even sure how to update the instruction properly for the current circumstances. As my understanding, the instructions from the WireGuard website aims to provide the best practices to install WireGuard. But unfortunately there is no best practice available for C8S for now, each method/workaround seems quite ugly to me.
Or should we just write down lengthy texts on the page to describe the situation? I think it will break the simplicity. Since the Stream is the beta/experimental build of RHEL. The user base is low and the demand of the instruction updating for that user base is also low. Consider that the CentOS Stream 8 does not actually mention in the instruction, only CentOS 8. I think we may leave the instruction in the current shape until we got some decisive solution to provide. There is a bug #2103865 about the recent WireGuard breakage which I submitted to Red Hat Bugzilla, and I don't see any response yet.