I think the chance of Nintendo games being released to PC is possible if most of the people working at Nintendo and Nintendo fans think iit is a good idea.
I highly doubt it, Nintendo is very strict about their IPs and they want you to buy their hardware. To be honest with you, I'm happy with some company keeping console exclusives alive. I prefer exclusives, you had a reason to buy a certain console. This whole "play games on multiple platforms" is eh IMO. I'm not really a fan of it, I know I'm probably sounding like an old fart but I miss exclusives.
They might, in case they sell emulators. Because it's super easy to make a case that all emulators of Nintendo games should give Nintendo the automatic right to own them, because of the hardware they made does the same tasks and more. They always have been on PC, so really it's a no brainer.
I think Nintendo may have a game streaming service for PC similar to Xbox Cloud Gaming if it is profitable fir Nintendo, and enough people want to use it.
Nintendo already publish a few games to Mobile, so I think Nintendo could publish games to PC because many people are interested in PC gaming like how many people are interested in mobile and console gaming.