If I'm a Switch owner I don't need xCloud on my Switch anyway. My TV or set top box or tablet or phone or PC likely will have an app for it, just like you don't need a Switch to watch Netflix.

MS doesn't need full cooperation here from Nintendo to benefit. 

The Xbox 360 iterations of Forza should be pretty easy ports to Switch, same for the Master Chief Collection, (just maybe cut the Xbone graphics of Halo 2) and if Mortal Kombat 11 can come across to Switch in pretty good shape, Killer Instinct should be doable as well.

Ironically the biggest challenge might be Rare Replay as some of the emulation involved might be troublesome on the Tegra X1. (I'm no expert, anyone who knows better is free to correct me)

Jesus H. That display looks horrible... Hard to believe that is from the Gamecube era...

Halo and probably Gears and Forza would all sell 1+ million on the Switch. There is not a lot of competition in those genres and likely Nintendo would allow Master Chief into Smash Brothers to boot. 

Witcher 3 sold 700k on the Switch in 2 1/2 months and likely 1+ million in under 6 months ... at full price. Things like Halo would do very well.

There were 9 3rd party 1+ million sellers on Switch in last fiscal year alone (not total, just the past 12 months), almost definitely Witcher was one, Mortal Kombat 11 would be another. 

A Halo Collection on Switch would crush 1 million copies easily, probably talking 2+ million. 

Honestly, I would not be surprised one bit if sooner or later we will see MS IP's on Nintendo systems. If there is one manufacturer who clearly has no real interest in building hardware that is MS. They know that they still need the Xbox Series Whatever to keep their old fanbase, but I doubt they will be manufacturing boxes 10 years down the line. As soon as they can, and see it profitable, they will sell Gamepass, XBLG, and XCloud wherever they can.

They are already bowing down to Steam as their windows storefront was a complete disaster, so yeah, doubt this is a stretch.

just like the bravias in 10 years will have a build in ps now/playstation?

btw you had captainexplosion agree with your point

I really don't know, in all honesty. If it is profitable, sure, I could see Sony go down that road, but thus far they experiment WAY more with hardware than MS. MS promised us VR/AR technologies for years now, and they completely abandoned it. Sony introduced AR to the mainstream almost 2 decades ago and has one of the few reliable VR ecosystems already. It's pretty clear they think that hardware will be still important even in a decade.

And Nintendo.... well they pretty much build their games around their highly creative hardware kits. It's really a market perception and it's obvious that the Japanese manufacturers still think more about it, than the US manufacturer. Which will be the right choice, only time will tell, but from the outside, it's pretty glaring. This interview is pretty much a clear sign that this is their strategy:

https://www.theverge.com/2019/6/11/18661247/phil-spencer-interview-xbox-project-scarlett-xcloud-e3-2019

Also, cheers for having CaptainExplosion agree with me This is one day to remember

I really don't think that losing the exclusivity of your games over 1m units-sale is a worthy endeavour, especially considering how aggressive all fanbases are nowadays with the "exclusives" talk. That would be one heck of a bad PR for just 1million units sale.

Well this is a hard no from me. I’m ok with Xbox sharing their smaller titles like Cuphead and Ori and games that were all ready multiplat like Hellblade and Outer Worlds. But their bigger games should stay within the Xbox ecosystem. Unless Nintendo willing to share I see this as very one sided. Not like it’s locked behind a closed wall, you have PC/Game Pass and Xcloud coming up. It’s the most accessible 1st party games you’ll ever find.

Nintendo is not releasing games on the XBox, MS can sit around and wait 20 years if they want that to maybe happen (and it still likely wouldn't). 

If MS wants help now in making actual inroads versus getting their ass kicked by the Playstation over and over again any time soon they are going to have to try things that are out of the box. 

Making the huge Nintendo audience XBox friendly/leaning is more than a reward in and of itself. It's like if two countries are in a war against each other (Sony vs. MS) and you have a massive third country with large resources that is mainly independent and not really involved in that main conflict any more ... if one of the two countries could turn that independent country into a safe-zone where they could get supplies and launch attacks from, that would be a huge, huge advantage. 

MS needs to look at things strategically here, otherwise they will keep getting beat up by Sony. 

MS are already doing well on the Switch, they have nothing to lose and only things to gain by going all in. You turn Switch fans into Halo, KI, Forza, etc. fans and they will be more likely to buy an XBox when it comes time for new franchise instalments that will be only on XSX. Or require an xCloud sub. Either way MS gets what they want. 

What's the endgame here? To actually sell more XBoxes or to get into a pissing match like a 9 year old over "boo hoo, this isn't fair?"? If MS wants to actually move the needle on the rut the XBox hardware brand is courting the Nintendo fan base would be strategically smart.