In the original release, you had to supply your own API keys. It cost money to run it, I found I can spend as much as 9 dollars PER DAY playing it. But people kept giving the feedback that they didn't want to setup the account and deal with all that hassle.
They needed to monetize it somehow, and this is how they are going with it. It makes sense, you can't expect them to release a one time purchase game that costs them potentially hundreds of dollars a month by player costs. The whole project would go under water. It isn't predatory, it's the only option they have.
I would know, I am developing my own AI-integrated project. And yeah, the costs can add up. I had to scale back my project because just TESTING it before I went live with it cost me over 30 bucks.