Yeah, still kinda low in a paid game.
Ads or Capcom cuts off support for the game? Updates aren't cheap and the money coming in is most likely less than the money going into development. Sales for season 3 season pass was probably terrible, which is most likely why they didn't announce a season pass for season 4. Besides, the way Capcom Cup played out, they probably put the ads into the game to streamline things for tournament streams. They're probably also gearing up for F2P SF V or SF VI will launch F2P.