Keeping OSRS is the best thing you could do.... It give old membs somewhere to go for a challenge (and lets face it, no GE IS a challenge - lol) and new membs somewhere they can learn. (Its actually easier to learn about the combat triangle in OSRS than in the main game, where the choices can be overwhelming at first).
So big YAYS all round.....
You had to look, didn't you? This spoiler got scared and ran away, shame on you!
Can there be an actual f2p on oldschool. Most players who are already paying for membership prefer to stay p2p and not go on nonmember worlds. Many items in the p2p economy were reliant off of the f2p community. This might even bring more players into the game and encourage them to get membership.