According to Dan Garry, the Apps team is now sending sections=all instead of sections=0 on recent iOS app requests. The result is that apps will be underreported, since the existing implementation of the pageview definition does not know this.[0]
I've filed a phabricator ticket,[1] but this is just a note to make sure it's surfaced more widely - pageviews-based requests using the "New" definition are not currently reliable for apps. This is the Nth reminder to !analytics that if you're planning on (a) asking analytics for data and (b) getting useful numbers, it's probably nice to tell them about this sort of change /before/ you make it.
[0] https://github.com/wikimedia/analytics-refinery-source/blob/master/refinery-... [1] https://phabricator.wikimedia.org/T93255