I usually get Sony and Nintendo (skipped NGC for various reasons). I think of WiiU as hardcore as it has some of the hardest games this gen especially if you count 100% completion. I will buy 3rd party for whichever one runs it more stable and at a higher resolution and generally plays better on. I love the parallel design on the controller's joysticks and I hope Nintendo sticks with it next gen and if so I'll gladly play my 3rd party on theirs if it's better looking on theirs.
I would still buy PS5 because I actually value Sony's exclusives over 3rd party and Nintendo exclusives and I would probably still spend the most time on it with free games and all the first party stuff I love but it would be pretty even if all the 3rd party were bought for Nintendo. I like my trophies but not enough that I would not buy the best version of the games.
The only thing is I normally buy Nintendo systems at $200 or less just because I don't perceive their value to be as high as Sony ones. I only got a WiiU when it was $200 refurbished (looked new) so if it were $400 like a PS5 or something I may have to stick with the PS5 for a couple years. Then again Nintendo has done more powerful for less before with Gamecube so I could buy it sooner.
To summarize the only things that may change if this scenario were to play out would be me buying 3rd party on Nintendo instead of Sony (if they were the best versions) and possibly buying it later (depending on price).
