An absolutely awful original post, but I think that might have been intended.
There's nothing unusual about the timing of Switch because the 3DS launched in early 2011 and was due for a successor after six years. There's also nothing unusual about a failed console (in this case the Wii U) getting a successor after only four to five years (Saturn, Gamecube, Xbox). Anyone who believes that Nintendo was somehow obligated to drag out the 3DS for eight years and the Wii U for six years has no clue whatsoever. Due to Switch being the successor to both the Wii U and 3DS, it was always bound to be that the Wii U and 3DS would have different lengths for their respective lifespans. The odd one out is Microsoft whose Xbox One has no business to have seven years before its successor is out and it really shows in its weekly global sales more than one year before Scarlett is supposed to launch. Nintendo started the next gen when it was due based on historical standards, Microsoft was oblivious to their situation. If Microsoft had made appropriate moves for the console business, they would have forced Sony's hand and then the generation Switch, Scarlett and PS5 would have launched closer to each other than it will actually do.
You spend time talking about a Switch Pro when Sony and Microsoft will have their hands full with competing with Switch as it is. Nintendo won't be hiding any hardware sales. Marvel Ultimate Alliance 3 is a Nintendo game.
As for what Nintendo's plans were... the return to #1 in the console business. Nintendo sold the most consoles during the fiscal year ending March 2018, the one after that, they'll be #1 in the current fiscal year too and there's a very high chance that that streak will last beyond that. One additional year is a given anyway.