And even then if they have the option, the entire process is designed to make the user feel as uncomfortable as possible while doing it. Disabling perfectly unrelated features (e.g. fast boot), going through Scary Boot Prompts, etc. are NOT acceptable requirements for booting a non-MS OS.
It's not the first time a vendor disables the MS UEFI CA signature by default (e.g. Microsoft itself has done it on ARM _and_ x86 Surfaces).
And even then if they have the option, the entire process is designed to make the user feel as uncomfortable as possible while doing it. Disabling perfectly unrelated features (e.g. fast boot), going through Scary Boot Prompts, etc. are NOT acceptable requirements for booting a non-MS OS.
It's not the first time a vendor disables the MS UEFI CA signature by default (e.g. Microsoft itself has done it on ARM _and_ x86 Surfaces).