While Miitomo will be the first Nitnendo mobile game in March 2016 and will be a free-to-play game, the Wall Street Journal is reporting that “other smartphone games will be pay-to-download" – while it’s possible that other free-to-play games will come out, it also could mean that other free-to-play games will exist. We’ll see just how this all shakes out in the coming year or two.
This is an interesting move, but considering that Nintendo has some of the most powerful IP in gaming, and have helped turn around their finances through selling plastic figurines, they could probably do well enough selling games at an upfront cost to go along with free-to-play games, depending on the audience. We do know that DeNA will operate the games, while Nintendo will figure out how to use them to get people to buy more Nintendo systems. Interesting stuff, and it seems that we really should expect the unexpected with Nintendo.