barebone server is a thing fwiw: A product that comprises a motherboard installed in a case with PSU. Customer adds CPU, memory and storage devices to make a complete usable server. We typically buy servers in this way because figuring out what motherboard fits in which case is a pita, conversely buying complete servers is more expensive and potentially runs into inventory issues at the vendor. So possibly they are running bare metal servers that were also barebone.

Ohh, you're absolutely right!