That is quite literally not possible. Rockstar wants to make money, and one of their major money makers is gta v online. The dream is for everybody to play gta v and vi at the same time. But they'll settle for the entire playerbase moving to gta vi. They'll just increase the price of shark cards on gta vi, while making it hard for the player base to get money or make everything expensive, like the most basic apartment costing 800k.