Those particular ones, no. But Nintendo's track record of honesty and transparency when it comes to Breath of the Wild is sketchy at best.

Wouldn't surprise me, even as a wiiu owner that isn't buying a switch i wouldn't mind if they cancelled the WiiU version.

No.

doubt it. A Wii U port is an extra 1ml sales.

Is there history of Nintendo ever cancelling a port of a game they promised for a platform?

They weren't ports, but they did cancel Super Paper Mario, Raven Blade, Thunder Rally, Retro Football, DK Barrel Blast, and Kirby's Return to Dreamland for Gamecube, Dinosaur Planet and Kirby's Air Ride for N64, Starfox 2 on SNES, Pikmin 3 for Wii, etc.

I guess having some worry is justified.

Sounds good! I always knew you were great at making plans, Zisbest.

It doesn't make sense to you, but for Nintendo it could if that means higher Switch sales in the first year, because they need to make the Switch a success.

Sometimes we forget, or not pay attention, that we're talking about business, and sometimes what makes sense from a business perspective is the opposite of what we, gamers, want.

I feel the same, if they don't launch Zelda BotW on Wii U I'm done with them.

But you and I, and the rest of member of this site and others, are the minority and we have top accept that we don't represent the whole gaming market. Cancelling the Wii U version of BotW may mean them losing a few hundred consumers (and it remains to be seen how many of them would end up buying the new console at a later date), but if that means selling several thousand units more of Switch to the general users, they may find that it's worth it.

Mario kart isn't that impressive. I've had my wii u on a projector, its simple repeated texturess, missing anti-aliasing and low resolution. It's only its art style that is fantastic and truly beautiful. Nothing complicated about the wii u either,  it's 3 very old 32bit ppc cpu's  developed in the last century with a huge history of documentation and development and a fairly standard low performance radeon gpu. The ps3 has all the cell processors and the 360 multi-threading plus  both have more primitive architecture gpu's that rely more on the cpu for assistance especially the ps3. In one generation alone Radeon reduced the load on the cpu by 30%. The only issue with the wii u is trying to make such low performance hardware even match ps3 and 360. I'm sure for the gpu they had a little more performance to work with but for the cpu considerably less. Anyway the results are in now so to speak and we can see exactly where the wii u wins and fails in performance terms. You only have to look at the wide range of comparisons at digital foundry to see the results. 

The wii u was always good enough for Nintendo games but where it goes outside of its comfort zone requiring realistic physics engines,  real world textures, lighting and weather etc it fails horribly. Cartoon graphics fine. Even Mario 64 on the N64 is still an attractive game for me.

At the start I did the usual its the developers that are lazy or its a rushed port excuses but the reality was everything performed at that level even games developed by hugely competent development studios. It was the same as ps2 where development times were actually much extended on wii u because of the weak hardware. They had to find new ways of compensating for such low cpu performance etc. Often they couldn't do a rushed port that would come out at the same time as other versions they had to spend much longer on wii u developing games and still the games were released with performance lower than ps3 and 360.  

Just think of what the wii u would have been if instead of 3 awful cpu's at 1.2ghz it actually had 1 of the same plus 2 much more powerful 64bit cores all at 3.2ghz and its radeon gpu had 800 gflops. Memory bandwidth was increased from 12.8GB/s to 25..6GB/s.  That console would have had much enhanced versions of ps3 and 360 games and slightly weaker versions of xbone and ps4 games plus Nintendo's own creations would have been capable of 1080p anti-aliased graphics  with a rock solid 60fps frame rate. All that  would have been possible even at the same retail price point just with a smaller margin for Nintendo.

Much of Nintendo's own development has been massively restrained by such weak wii u hardware that its been difficult for Nintendo games to appeal to a wider audience.