except when you hire a senior engineer as a contractor it is a different relationship to a code monkey contractor.

If you want them to do sprint planning / estimations / train interns it is a lot closer to a traditional employee than a "we pay $XXX a day for 7.5hrs of coding" contractor

I think this is really context dependent. It sounded like the author was a senior engineer deeply embedded in the team and a part of standup, sprint planning, retros etc. Which is different to farming out a specific component to a specialist to work on in isolation.