I think both closers kind of work. ISHFWILF suits the theme well, it's just that it's never been a closer before and will take some real getting used to.
One I've always sort of thought of as being a suitable closing song, but it just doesn't sound as good as it can.
honestly, I think the biggest problem with ISHFWILF as the closing song is the audience is barely singing along! If they sang along really strongly and loudly, it would, I think, be completely transformed and could really work.
Yeah they probably thought the audience would keep singing "But I stiiiilll haven't found what I'm looking for" or "there is no them, there's only us". Bummer audiences went lame after the invention of smartphones.
