Great article, love their effort to innovate but misleading IMHO. Android is doing it already as you’ve put it with their Chromebook, but how many of those apps are cross-plat Flutter, React-Native, Xamarin, NativeScript or hybrid Cordova / Ionics? Get it?
WASM development is on github: https://github.com/webassembly
So, to conclude, I think it is a shot in the foot. But again, they are huge company and they can put a lot of resource into such project. But, having devs to accept it and spin it out in a good and developed ecosystem will be a much bigger issue then the idea itself.
Not to sound too biased (which I am, doing web dev mostly) but I also write desktop apps with C# and do welcome Blazor/WASM to the desktop realm.