3rd party software development in 9th gen in the current circumstances.

[Salnax]

I'm thinking the PS4 and X1 will continue being supported for a while longer. Same as all the fairly successful consoles in recent memory.

• One of the best-selling games on the PS1 was Harry Potter and the Sorcerer's/Philosopher's Stone, which was released a year a year after the PS2.
• The PS2 was technically replaced by the PS3 in 2006, but as late as 2009 it was still getting million-sellers like FIFA Soccer 10, PES 2010, and DDR X2.
• Even after the GBA had to compete with the DS and PSP from late 2004 onward, it continued getting plenty of games for a couple of years. Pokemon Mystery Dungeon was originally a cross-gen multiplatform game as late as Autumn 2006, and VGChartz mentions that a couple of GBA titles sold over a million units despite launching as late as 2007.
• The DS was succeeded by the 3DS in early 2011, and in 2012 still got a main series Pokemon game, Pokemon Conquest, and multiplatform LEGO games.
• The Wii was replaced by the Wii U in 2012, but got its last million seller in 2016, despite mostly dying down after 2010. (Just Dance on the Wii was quite the phenomenon).
• The PS3 and Xbox 360 were phased out in 2013 after what were fairly long lives for consoles, especially the X360, yet in 2015 and even 2016, games like Call of Duty, FIFA, Minecraft: Story Mode, NBA 2K, Madden NFL, LEGO games.

Unless hardware shortages remain in place for years to come, I see no reason we'd be getting more development on the Switch than usual.