[jp10558]

It used to be for standardization, but I've seen more commercial tools provide Debian / Ubuntu support than Red Hat lately, since the late 2010s. I also think the amount of changes and the issues with licensing here mean that more people might up and convert to Debian than before. But IDK. I also hear that more ML work is done on Debian, and yes - with the containers becoming big - less need to run any particular linux, so I could see swapping out the underlying Linux.

And from a company perspective, Red Hat has already done a big swap out from satallite to Foreman / Puppet to really pushing Ansible. Similarly, they've stopped doing oVirt in favor of cloud style OpenStack, nee OpenShift. Which is great if you're building your own cloud fabric, but not really the VMWare / HyperV competitor oVirt was which is something lots of mid size orgs need. ProxMox still seems to be going.

And for people who aren't paying for support - I imagine they have skilled in house teams that can certainly figure out Debian if they've been orchestrating CENTOS and now Alma say.