It's a ridiculous notion. HALO, Gears, Dead Rising, Quantum Break, Sunset Overdrive, Recore, Ryse, ect... all strong single player games.
Sony had an unusually amazing quarter with Horizon, Nier, Nioh and Persona. One of those is first party and the other three are Japanese developers that chose not to release on Xbox One most likely, because of the lack of XB1 sales in Japan and the rest of the world. How big is the market for those games in areas where the Xbox is doing well? Probably not enough to warrant a release and if MS decided to pony up to publish they would probably lose money for a small bit of good press.
Everyone acts like Sony is solely pumping out these games, but that's not the case. They are doing great and their first party releases have been really good. MS need to step their game up, but anyone that thought they were going to abandon or greatly diminish single player games is just delusional. The only people reading into that quote to that extent are fan boys looking for ammo for console warz.