I think its more than just them using it for their apps. I think they want to turn Electron into a reusable Desktop UI framework for Windows and given the fact they now own GitHub they can force that for the Windows rendition of Electron. It all seems like almost a bad idea if it makes Edge too reliant on Chrome. I really was hoping Microsoft would instead have fully open sourced Edge. Edge could use some community love to make it a sweet out of the box Windows browser.