Hyperscale exists as a term pre-LLM-hype. It mainly exists to describe the kind of datacenteres that companies like google and amazon have been building for at least a decade now: very large, very highly integrated and customised hardware, with a focus on cloud deployment and management strategies. This is to distinguish from just a large datacenter built with commodity server parts from a set of vendors (i.e. the kinds of servers 99% of people will be able to lay their hands on. Another way to put it is that if you're not writing your own BIOS/BMC/etc, you're probably not hyperscaling).