It was inevitable. The reason why there was a separation between home consoles and handheld consoles in the first place was technology. Handheld-specific games were a necessity, but obviously every console manufacturer would have prefered it if the same games could be played in a stationary and portable manner.
Sony exiting the handheld market certainly played a major role in Nintendo making a single development environment a reality, because if Nintendo hadn't done that, they would now be the only console manufacturer with two development environments and therefore at a significant competitive disadvantage. While in early 2014 Nintendo talked about consoles that would be like brothers, they ultimately managed to put everything into an all-in-one-device, making everything easier for themselves, third party developers and gamers.