Microsoft to use steam to sell games as well

So Microsoft has the windows store at the moment to sell games on PC, but they are attempting to get their games on Steam possibly for more sales, etc.
Since some of Microsoft’s older games are found on Steam (Age of empires II for example), the higher profile games like Forza 6 Apex and Quantum Break being on the window’s store only. According to Spencer, the games really aren’t selling too much, and that they were annoying to be over 50 GB, etc.
Phil did not say what games will be sold on steam, but doing so will open up Xbox titles to a larger variety of audiences.
Source