It is likely just a glitch. Amazon is not likely to pull the Kindle iOS app when it happens to be the flagship of the Kindle apps. The iOS version of Kindle has always been much better and with more recently added features than that garbage they release for Android and the Fire. Kindle app on my iThingies is way better than the Kindle app on my Fire HD6. It makes no sense to me why Amazon doesn't stress the Fire app more.

Also don't forget that the Search function in the iOS app store is total garbage. It is not uncommon for Search to not find stuff that is there.