Listen to the lyrics of this song, and you will hear the line "Like a record that's skipping," describing the singer's unsettled feeling. Listen to the music of this song, and you will hear a cool little 9-beat creating an odd skip that perfectly emulates the same feeling. That kind of control over sound and sense is a big reason Arcade Fire songs earn a deeper attention from me than many others' ditties.
The rhythm of this song is really outstanding. I happen to be a fan of odd time signatures that submerge as invisibly as possible into the song, so that the music seems to lose sense of a set time signature altogether. Many songwriters use time signatures in order to stand out - they want you actively counting the beats like stars on a flag. "Modern Man" goes the way of submersion.
That 9-beat measure ends with that awkward skip, sure, but how many non-musicians really get what's going on there? And how many more people fail to recognize how seamlessly the song morphs between that 9-beat and more straightforward 8-beats, almost at will, purely in support of the melody rather than forcing the melody? The outtro even tosses in a few one-off 7-beats. What's the difference? 9-beats, 8-beats, 7-beats? How can the addition or removal of just a beat or two be important enough to enforce with such specificity, especially when this band includes so many members, all of whom must be coordinated on these subtleties?
And the truth is, so much of art is in saying, "No, these are not small details. The small is the large reason why I'm doing this."