It seems like they were trying to create a “gaming eco-system” with project x-cloud, mixer and x-box. The problem with this was mixer was getting very little users compared to video-streaming giants like Twitch and Youtube, simply because everyone was already on Youtube and Twitch and those companies had established their dominance and no-one wants to move to a smaller website with way less users. Now Microsoft can leverage Facebook’s massive scale, over 2 billion users, to attract more potential users. Whether this would be succesful is up for debate.
Secondly, I believe that Microsoft can leverage Facebook’s massive scale to promote project x-Cloud. Microsoft are already quite a bit behind Google in this regard, so taking advantage of Facebook’s reach will be really important
Disclaimer: This information is only for educational purposes. Do not make any investment decisions based on the information in this article. Do you own due diligence.