If you look at the list of architectures, you can see that the collection does contain a number of artifacts related to actual VAXes: https://vaxbarn.com/collection/arch
Maybe those were the beginning of the collection, and how it got its name.
Also, the curator is a kernel engineer at VMS Software (see "About me" at the bottom of the home page), so he definitely knows what a VAX is.
You're completely missing my point. Of course a museum of retrocomputing would contain DEC VAX et al.; nobody said otherwise; nobody quibbled the bona-fides of the curator.
I legitimately asked how they actually manage with the SEO namespace having been namejacked by another unrelated topic, which is heavily associated with endless flaming. It occurred to me that I haven't seen the term 'vax' on social media in the old sense for several years now. It's been overrun. (If you go on Reddit and search "vax museum" or "Can I see a VAX in a museum?", zero of the top hits are relevant.)
Maybe those were the beginning of the collection, and how it got its name.
Also, the curator is a kernel engineer at VMS Software (see "About me" at the bottom of the home page), so he definitely knows what a VAX is.