"The Register submits it would be a brave buyer that ignores decades of historical case studies about the perils of lock-in to proprietary platforms and makes LinuxONE the bedrock of a new IT stack."
This.
Bare metal? LPAR anyone?
They are talking of "vCPUs", so I suspect that is an LPAR.
Maybe. Could also be Linux guests running under z/VM. z/VM itself might be running in an LPAR.
Are there any cheap big-endian cloud VMs available?