We love you Mr. Iwata, i shed tears when you passed, such a sad story :,(

I haven't shed tears for anybody who I didn't know personally before. Iwata will always live on through his legacy.

Legend

Well....Kimishima sure didn't have much to do with it. His specialty is business, not hardware design. Switch was indeed Iwata's brain child and was probably in development for more than 4 years as Iwata said Nintendo were already thinking about their next console idea in 2012 when the WiiU launched. The Zelda team was also told sometime in 2015 that Zelda would have to be ported to Switch as well which by that time I'm sure the console specs were locked internally around the beginning of 2016 by which then patent safety and manufacturing have to take place...manufacturing didn't only take place in 2017. The bulk of Switch's development was more than likely helmed by Iwata and most likely Takeda. 

I hate thinking his last months were spent stressed as the CEO of a company that was in a slump he felt responsible for (despite practically ressurecting it with the Wii and Gamecube). Hopefully he didn't let it get to him and was excited about his last project (Switch).