the thing is that Microsoft Hyper-V is a method of running your VMs on BareMetal.
- it's a similar way, as the BareMetal Host system is run.
so, that's supposed to run your VMs much closer to Native Speed - - like the Host system is.
it's also a competitor to using software methods, such as those from Oracle & VMware
- which are so much slower, have to share resources, etc etc.
so, yeah - M$ is trying to be up & cozy with all other operating systems,
and as such, those Linux Systems are the obvious target(s).
& that Ubuntu system, would be a prize target, indeed.
then again, from the other side - - most folks, who are running any Linux based system,
have usually made a deliberate move away from all things from Microsoft,
& thus would be rather reluctant to use any system from Microsoft, to "run their Linux system"
whether that's within / adjacent to the Microsoft Host System, or what ever.
there are supposed to be "some advantages" to a select few, who do run both Windows & Linux systems,
but, they would be a small group, who would benefit from this method, whereas the majority of Linux Users,
would not see any benefit in using this method, at all.
as an aside - - you have to "upgrade to Windows Professional" to use the function,
ie: it's not available for those who do use the Home Edition of Windows . . . .
an cynical person, could also it's a way of encouraging folks to "upgrade their windows"
- to a more expensive version of the Windows system.