So I did the legwork and in terms of number of songs, this is the shortest U2 show in over a decade. They haven't done a show with fewer than 22 songs since 24 November 2006, Auckland, when they also did 21 songs.
It was fairly common to have just 19 songs at Elevation Tour shows, but since then gigs with fewer than 22 songs are very rare. There was one with 20 on Vertigo's third leg, and handful with 21 sprinkled across the tour. Otherwise, every 360 and IE Tour gig, and almost every Vertigo Tour gig, has had 22 or more, with the most being 27 at some second-leg IE Tour shows just eighteen months ago.