The v2 part here really just refers to the fact that it’s version 2 of the specification. Consumerrs only need to know the term USB4 and the speed that their device operates at. It’s sort of like complaining that the ietf has terrible naming schemes because HTTP is defined in half a dozen RFCs with 4 digit numbers. This versioning is just meant for people developing USB things.
Actually this article here is one of the few times where even mentioning the version 2 part is reasonable since the details of these specifications actually matter to kernel developerrs. For everybody else it’s just USB4 80 gbps.