A junction in Raku, when given as an argument to a function, automatically applies this function to each of the junction's element and the results are combined into a new junction as a result.

I don't know, seems like a pretty clear parallel to me. And since the Powershell's behaviour is quite often undesirable, I agreed with the original commenter that perhaps the junctions could also be somewhat annoying to use instead of just working normal lists: after all, "s in ('this', 'that', 'other')" is about just as clear as "$string ~~ “this”|”that”|”other”" but doesn't require support for magical self-destructuring containers in the language.