Niantic:

We recently discovered that the Pokémon GO account creation process on iOS erroneously requests full access permission for the user’s Google account.

It’s nice they’re trying to fix it. But, really? That never came up?

UPDATE 7/14: The update has been released and it’s a good thing, too. Out and about playing with some other people we found the ones logging in with Pokémon Trainer Club accounts had periodic but extended outages and weren’t able to connect. Those logging in with Google accounts had none. (Your mileage may vary.)