It's known that iOS is the best platform to make money and targeting iOS makes more sense because of that. They probably have an idea of how much they're willing to spend to fight Apple on this because if they win it will be huge for them and they stand to make more than releasing on Android. This is also putting them directly into the news and will reach those Android people so it almost doubles as a genius marketing campaign to fight Apple. I highly doubt they see all this as a waste of money and time and I can see them fighting Apple until they are forced to release an Android app to recoup the money they've lost.

Android users are notorious for not spending money (IIRC Apple users spend double the amount of money on subscriptions vs Android users) and it's unlikely Android users would tip content creators, or even watch the content they're putting out there.