My issue with believing this is the comparison that was made, the XBox platform is primarily a third party driven platform that had a very small amount of notable first party IPs. Likewise the PS of platform is primarily third party driven as a platform. The difference between the XBox and PlayStation is pretty much down to exclusive pieces of software. PlayStation while still TPD, still had first party exclusive software at launch that helped it with consumer interests. And XBox had exclusive features to it selling the the hardcore consumer base that were going to adopt it whether it had 3 or had 30 first party games.
Nintendo’s approach is not really like that and they depend more on FPS (first party software) to drive their platform adoption. Along with said FPS it brings to them the most revenue and helps in penetration in the market.
Nintendo launching without a first party title that can sell the system would be uncharacteristic and would in essence go against their whole ethos in the market.
It’s not that they don’t care for third party, they do, but they don’t depend on third parties taking up the reigns to do that job. They value third party software as an extra and treat them as an extra bell and whistle to the main course of why a Nintendo system is bought.