Earlier quoted context omitted.
Yup Linux has had a similar feature, kexec, for several years.
Everyone I talked to about it since has said "nobody seems to care enough to bother completing it" It is kind of a niche feature, really.
Linux has this create feature of being able to include the operating system in the initrd. Put this with a nice PXE infrastructure where you pxe the OS and download the initrd with the OS in it. Then you simply kexec to upgrade or downgrade the entire operating system in ~30 seconds. I used to manage a production environment that worked exactly this way for several thousand nodes.
Not sure I'd call it niche, but yes, somewhat specialized.