At some point in the last decade or so HR at many tech companies have decided to rebrand themselves at "People Operations." And CPO as a title is the logical conclusion of this nonsense. You guessed the acronym correctly. Practically speaking it's the same old mundane HR department. They may use "Hey" in their email salutations or promote "Wellness" programs now but their primary purpose is still to protect the interests of the company not the employee.
I mean honestly "people operations", while not a good term, is still a much better term than "human resources". Always wondered who came up with that one, and whether they intended it to be used in real life, or just in dystopian sci-fi.