1. Mirantis did not acquire Docker Inc., they only bought Docker Enterprise. See https://techcrunch.com/2019/11/13/mirantis-acquires-docker-e... and https://www.docker.com/blog/docker-enterprise-edition/
2. k8s didn't remove dockershim for political reasons but because containerd was refactored out of Docker long time ago and k8s wanted to get rid of the extra layer. See https://kubernetes.io/blog/2022/01/07/kubernetes-is-moving-o...
3. Rate limits have nothing to do with the container runtime. Podman also has to get images from somewhere. And Cloudfront bills starting at $0.02/GB (assuming you pump 5PB+) have to be paid somehow. The rate limits were mostly in place to deny corporate CI users access to the Hub free of charge and force them to pay or deploy a mirror.
4. RedHat offers not only packages in RHEL but also support and it makes sense they will offer packaging and support only for podman (a RH project) going forward. This does not concern us who don't pay for RH support.
Having said that, Podman is a nice evolution of Docker. Though I am not sure how much I can trust the rest of the article given how the intro twisted so many facts.