Earlier quoted context omitted.
But is that a skill that is required for lots of positions?
Recursion is a fundemntal part of programming, beyond the self-taught junior yes I would absolutely expect every programmer to be able to do it. You learn it in highschool level programming classes & first semester intro to CS college courses. Even if they won't specifically need to use recursion in their next job it marks them as someone not serious or about programming.
I mean, I would be worried if a candidate is not shy to use recursion that this will blow up software perfomance. (But then probably after hire the senior will tell: dont use recursion here)