To be fair, I'd advise against choosing core infrastructure components based solely on a recommendation in an HN thread.
You should do your own research, obviously! I am comfortable enough with the Deis brand to say that it is a solution that does not even remotely rival the Linux Kernel in terms of complexity. Kubernetes has API stability, and you can count on APIs that are not marked "alpha" or "beta" to be around in the same form as long as it is still called Kubernetes.
Deis is made of small, totally understandable parts. It is not a monolith that you need to weigh heavily in your conscience whether to allow it into your infrastructure, in case you can't find support for it at some future date... you can mix and match components, if you find one part does something that your infrastructure was lacking!
I'd be glad to elaborate on my strong suspicions, but tl;dr the last few days I've been scrambling to figure out how I'll get my issues resolved, now that the Microsoft dev team I had working on them for free is going somewhere else.
I've been raising every issue I can think of so I can get eyes on it before it's too late. And so far, I don't see anything that I think I can't solve for myself. My short list of issues, I've been able to solve almost all on my own! I have a lot of knowledge about Deis, I've been around for a few years, but I am not a core dev and I have never contributed any commits.
My impression of the codebase is that it is uncompromising and extremely comprehensible. There are at least about half a dozen of us that it appears will be sticking around; we don't want to undermine Deis and Microsoft's EOL notice, because "no breaking changes" will make our job easier as maintainers into the future. The first person to say the wrong thing, may wind up responsible for a fork. It is a delicate time, but I hope to convince some people that it should not be completely discounted because of this news.
But I don't really know what's going to happen to the project. It could be that development continues on Raspberry Pi and the project loses its focus on cloud platforms, because it's cheaper to do the development on RPI. And that might be fine for cloud users (or, it could be fine until your cloud provider makes a breaking update! More likely I think than K8s breaking APIs that are marked stable.)