Things like -48VDC bus bars in the 'telco' world significantly predate the OCP, all the way back to like 1952 in the Bell system.
In general, the telco world concept hasn't changed much. You have AC grid power coming from your local utility into some BIG ASS RECTIFIERS which create -48VDC (and are responsible for charging your BIG ASS BATTERY BANK to float voltage), then various DC fuses/breakers going to distribution of -48VDC bus bars powering the equipment in a CO.
Re: Open Compute, the general concept of what they did was go to a bunch of 1U/2U server power supply manufacturers and get them to make a series of 48VDC-to-12VDC power supplies (which can be 92%+ efficient), and cut out the need for legacy 5VDC feed from power supply into ATX-derived-design x86-64 motherboards.