I’ve read that before and it’s a good read too! Though I have few thoughts based on my own experience. Semantically I’d argue the DevOps interface mentioned in the article needs “engineering” in the organisation before developers can use it. It also needs maintaining, updating and planning. I guess “Consultant” or “Coach” would tick that box too, but I think it would give slightly wrong undertone about the level of involvement in the development of the processes used. So, I’d argue that DevOps Engineering can be, if not job title, at least job description.
As a side note, my own job title is not “DevOps” anything. The team I work in is not “DevOps”, it’s actually “infrastructure”. But when people ask what I do, I say “DevOps stuff”. So at least colloquially the meaning is clear to people in the industry.