Hiring for the Team, not just DevOps
What I see in the article is hiring for a team, not just DevOps/Full Stack. I also see hiring for DevOps is hiring for those focused on the flow, no matter what dept/org it goes thru. It's a value-chain that you want to focus on, and if that's full stack, great, but don't over-narrow the scope by just thinking Full Stack.
There are places for experts, and there are also places for people with broader experience.
The key to me is balance of speed and focus.
It's not to hire every 'full stack' you can find, it's hiring the right balance of people.
I do think it's likely many companies are a short those who can cross the group silos (dev and ops being typical) and breakdown barriers/blocks/sacred cows to meet value goals (faster deploy, higher visibility, lower mttr, higher availability, fewer regressions, etc).
For speed, hire for DevOps with a set of skills in the pipeline you are focusing in (deploy, metrics, response, tools, etc). The person with deploy experience may not fulfill all the needs of your visibility goals. Put together a team which spans the needs with appropriate overlaps in coverage to avoid those resource SPF.
Hire the expert to crack tough questions that those in the flow won't have time to focus on.
Beware thinking everyone doing everything is the goal.
DevOps Full Stack Engineer in that sense is a fiction.