ChromeOS is a Linux kernel with some software bundled on top to make a usable system; it is by definition a Linux distro. Curiously, it's even a GNU/Linux distro, as it uses glibc and GNU coreutils, unlike ex Android which is a non-GNU distro.
I will grant that it's a slightly odd distro, but is it any weirder than NixOS or Fedora Silverblue?
User-facing apps are browser instances and VMs, and under that is a pretty normal userland. It's still a distribution of software on a Linux kernel. And for that matter, is Silverblue any less a Linux distro with its read-only root and apps in flatpak/distrobox? Are Qubes OS or Proxmox with everything in VMs?
