Yes I was interested in that too. It suggests that in writing our own guidance for we should follow a similar style, but I rarely if ever see people doing that. Most people still stick to "You" or abstract voice "There is ..." "Never do ..." etc.
It must be that they are training very deeply the sense of identity in to the model as Claude. Which makes me wonder how it then works when it is asked to assume a different identity - "You are Bob, a plumber who specialises in advising design of water systems for hospitals". Now what? Is it confused? Is it still going to think all the verbiage about what "Claude" does applies?