According to rumored internal design documents, the Nintendo Switch will be releasing without support for free-to-play purchases. Under a heading titled, "E-Commerce Features Provided by NX," this July 2016 internal document states that there is no provision for the conventional style of selling free-to-play premium currency that can be exchanged for items inside a game. Instead, on launch, the Nintendo Switch will only provide support for standard DLC, one-time purchase items, or subscription-based purchases like online and season passes.
With free-to-play purchases being synonymous with smartphone gaming on iOS and Android, and slowly creeping into console games like Madden, it's great to see Nintendo put support for premium currency in the Nintendo eShop on the backburner. Nintendo's latest mobile title, Fire Emblem Heroes, has met some ire for its use of premium currency, and I'm glad to see Nintendo is keeping the distance between its mobile gaming and console/handheld gaming ecosystems.
However, in the same documents referenced above, it does say that timing for support of premium currency is to be determined. For now, it seems like owners of the Nintendo Switch will be able to enjoy their systems without a flood of freemium titles, but if Fire Emblem Heroes does well, Nintendo might decide to prioritize adding support for in-app purchases to the Switch.