I interpreted this section as saying something more along the lines of "if your job prevents you from engaging in coding as part of your day-to-day activities,

I interpreted this section as saying something more along the lines of "if your job prevents you from engaging in coding as part of your day-to-day activities, but you otherwise know how to code, then maintain involvement with coding by participating in code reviews." It seems that his intended audience is expected to know how to code.