Both Sony and AT&T are trying to sell their ownership of GSN Games, but, according to the article, there is also an option that Sony buys AT&T share of the company becoming the only owner. Looks like AT&T doesn't have any plans regarding the market of online games and are trying to get out. The value of GSN is estimated at $ 700 million.
https://www.fool.com/investing/2019/01/13/sony-and-att-want-to-sell-this-social-game-maker.aspx