Garrys Mod 2 will be called sandbox, it wont be a mod so hence the change of name and will be develop under unreal engine 4. So I will be super upset if it goes to epic store front first. But check the facepunch site and look at the games they made and the games that are still in development the game is called sandbox but they put it as s&box instead, so you can read it for yourself. I hope they add a decent modding system to it.