I'm not saying people can't take on other ideas and expand on them, but what you were saying was basically put these games into wow. Also, this would requires so much balancing and take so much time to develop that if Blizzard really wanted to make this, they would have to forsake their PVP, Raiding, and Casual audience to do so. So they would basically lose all of their subscribers in the process. If they make this a side project and develop it slowly so they can focus on PVP, raiding, and casuals, it wouldn't be finished for 5-7 years, and I doubt anyone would be playing wow by then. Your idea is unrealistic and is full of flaws.