Yes, I believe that's the issue. I recall with the Maps debacle, you had to wait for a minor update of the OS to update the app itself. Obviously the "iOS needs a whole OS update" can be seen in two ways, we know that going from say 7.0.1 to 7.0.2 means that a few things on the source changed and they recompiled, but for the end user, they don't receive a patch of say 15MB with what has changed. So in that respect iOS needs a whole OS update to update things like Maps (not the data obviously, but the source of the app).
The issue there is that for someone living in a country where data is expensive, a 10MB download is better than an ~800MB one every time there's some bugfixes/app updates. Plus from my knowledge, Play Store can deliver a patch of the app, instead of downloading the whole 10MB.