Between the assumptions and the rumours it looks like Nintendo has pulled it out of the bag as Super Mario Run hits 40 million downloads in under a week.
Confirmed by Nintendo America in a tweet yesterday, the fluid autorunner no doubt holds the record for fastest downloaded app - and it's not even out on Android yet.
Though the official earnings haven't been released as of yet, Super Mario Run was the highest grossing app on the iPhone after less than a day, and on the iPad the day after that. Of course, once it was all done and dusted the game dropped from its top position but the impressive figures remained.
It's still questionable as to SMR's longevity considering they're not planning on bringing content updates (or paid content updates at the very least) to the game. However this is Nintendo we're talking about, with a selection of mobile games in development and on the way in 2017, it's not like they'll struggle too much financially.
I guess we'll have to wait and see what the future brings for Nintendo on the mobile scene.