I really don't think this is it, if I'm being completely frank, because they already have an enormous amount of up front work done with making Windows PWA friend:

https://developer.microsoft.com/en-us/windows/pwa

I also am willing to surmise that they are going to put in alot of work re-working all their APIs that are exposed as Edge based interfaces into whatever engine they and up with here (namely chromium), so I don't think it would have been beyond them to put in the work to do something like they did with node and chakra core:

https://github.com/nodejs/node-chakracore

(which, btw, for now isn't dead: https://github.com/Microsoft/ChakraCore/issues/5865 likely for the reasoning I mentioned above)

I just don't buy it. I don't think easy electron compatibility is the main drive here.