Looks like while Nintendo are serious about their mobile game efforts going forward, they also don’t want to take resources away from their existing portable and console game development- this is probably why they are now looking to hire new developers exclusively for mobile game development, at both, their Tokyo and Kyoto offices.
This would indicate that the company plans to release smartphone games in earnest, but also that they have no plans to let the development of these smartphone games take anything away from their core console and handheld games- including games for their upcoming Nintendo NX system.
As of right now, Nintendo have released one title for smartphones- Miitomo, which launched earlier this year for iOS and Android, and was relatively major success. Later this year, the company plans to launch Animal Crossing and Fire Emblem for smartphones, with two more titles by the company due to launch by March of next year.