Love this. After Red Hat acquired Ansible I thought for sure they would cave on their open source principles, but they didn't . They really believe in open source, and we are all the better as a world for it. Disclaimer: I work for Red Hat but have been a fan decades longer than I've worked there.
A competing product (Harbor) is already open-source and part of CNCF. Quay wouldn't have had any future if it was to stay proprietary. Regarding RedHat (or IBM) truly committing to open-source, I'll believe when OpenShift 4.x is open-sourced.
Red Hat is very committed to putting the necessary infrastructure and organization in place around projects before they open source to make sure that the code isn't just available but can actually use community contributions. I don't have any inside info on this, but I wouldn't be surprised if OpenShift 4 is just waiting for that, or possibly to be in a stable enough state that the community can contribute.
Of course it's possible also that RH is keeping it closed for other reasons as well such as avoiding tipping their hand to competitors until their end goal is realized or something like that. I guess the point is I don't know, but given Red Hat's history of open sourcing even valuable acquisitions, I have faith that they will with OpenShift 4 as well.