Probably true, but meaningless
What matters is what platform the developers who are making popular apps are developing for. The kind of apps that are downloaded by millions of people. Not the people writing useless crappy me-too apps that do something that 50 other apps do, only worse. The people who think the requirement to buy a Mac (a Mini is only $500) and a $99/year developer license is a crazy requirement aren't producing the apps million use, they are producing apps hundreds use. Both the Apple and Android stores have enough fart apps.
I can well imagine Android having more developers, and more apps than iOS in the future, and the Android fanboys who said the number didn't matter back when iOS had 10x the number that Android did will scream it from the rooftops, and the Apple fanboys who screamed it from the rooftops before will now say it doesn't matter. It didn't matter before and it won't matter in the future, because most of the people producing the worthwhile apps will be doing them for both platforms.
The loser in this will be Microsoft, who will have a much harder time breaking in to be the THIRD platform that these guys develop for after iOS and Android. After all, who wants to write the same app three times, especially when between the much larger per user revenue on iOS, and the larger installed base on Android, the additional revenue of doing the Windows Phone port won't be enough versus just starting on their next great app idea for iOS and Android.