Welcome!
Gonna copy the post I just put in another thread a few seconds ago, haha!!
I don't think you have anything to worry about - there is no way they would release this game JUST to half of the mobile market...iOS takes up too much of the chunk of the mobile market to not release to iPhone devices. I think they are just waiting to put the app in the iOS store until they are comfortable with a release. I think they will add it to the store and a few weeks later, it will release. iOS tends to have a more strict guideline on the timeline for games to sit in "pre-registration" status in their store compared to Google Play.