Oh, dear. The Linux desktop fantasists are out in force today. In this case the fantasised solution to not applying updates to Windows is to replace it with something that doesn't need forced updates.
There are many organizations in the world that have has years long efforts to displace Windows. El Reg has reported on the city of Munich which after trying to use Linux for years has reverted back to Windows.
If Linux were a silver bullet we would have been using it for years already. Its not. It has many significant problem when used in any context but especially in a desktop context. Linux kernel updates often require that applications are recompiled and Linus Torvalds has explicitly stated that backwards compatibility of the kernel is not ever on the card for Linux.
For a the relatively small number of servers managed by a dedicated group of support specialists this may be acceptable and required re-testing and re-certification of apps an acceptable cost. But for a large fleet of end user computing devices it certainly is not.
Plus it presumes that some group of hackers in Leeds has even the vaguest clue about the range of applications that are used across the NHS. The difficulties of implementing GP systems across the NHS should surely throw up some warning flags.
But, I suppose, the managers who will ultimately sanction the notion of replacing Windows with some relatively untried Linux-based solution are the ones who also permitted the use of un-patched Windows in the first place.