Leading up to the release of Red Dead Redemption 2, rumors and high-hopes for other platforms beyond the PS4 and Xbox One getting the game swirled.

The two main subjects of these rumors were of course PC and the newest arrival on the console scene, the Nintendo Switch. Now, in an interview, Reggie Fils-Aime, Nintendo of America's COO, has spoken about Red Dead Redemption 2 and why it likely won't appear on the platform.
With regards to the rumors and speculation about Red Dead Redemption 2 on Switch, the general consensus was that an actual port is unlikely. Some named the console's hardware as the reason, however the fact that Bethesda's DOOM appeared on the console, and Assassin's Creed Odyssey saw a limited streamed release on the Switch in Japan, meant that technically it would be possible to, in some form, play Red Dead Redemption 2 on the platform.
The second main concern was the incompatibility with Nintendo's profile. In spite of the DS, Wii and Wii U all having games with violent and sexual themes in their libraries, some still think Nintendo is so hell-bent on retaining their family-friendly persona that Red Dead Redemption 2 would have been too graphic to be picked up by the company. We now know that neither of these suspected issues had anything to do with the lack of a Switch port of Red Dead Redemption 2.
Speaking with The Hollywood Reporter, Fils-Aime touched upon the topic of Red Dead Redemption 2. He spoke highly of the game and outright said that they [Nintendo] would welcome the game on their platform.
However, RDR2 had been in development for years already when Nintendo revealed their new console to publishers and developers in the industry. Since Red Dead Redemption 2 was the first game Rockstar had developed from the ground up for the current console generation, the underlying code was tailored specifically for the Xbox One and PlayStation 4.
We’d love for it to be [on Nintendo Switch]. But again – and this is where there needs to be an understanding of just the development process – Red Dead has been in development for years, time that predated any communication of Nintendo Switch. So, from the developer’s mentality, they need to move forward and finish the game they’ve been working on and then be in a position to look at other opportunities.
Red Dead Redemption 2 was extremely far along in development by the time Take-Two and Rockstar were notified of the Switch's existence, and the game had already suffered two delays meaning that the dev team really wasn't in a position to take on a new project, porting the game to Switch.
While all this this doesn't exclude the possibility of Red Dead Redemption 2 making its way to the Nintendo console in the future, it makes it clear why it hasn't happened yet.
Take-Two has been supporting the Nintendo Switch with games since day one, with some of their IP appearing in the console's announcement trailer. This clearly shows that both companies are keen on co-operation, so don't let those hopes of a future Nintendo Switch port of Red Dead Redemption 2 get dashed quite yet.