I'm Loving's Hitman's Strategy

While most game companies forces you to re-buy the same items over and over again each year. I.O. decided to take on a different approach by having Hitman 1/2 playable inside of Hitman 3 if you own the games already.

Wouldn't it be nice to be able play play gears of war 2 from within gears of war 3? Why not have more games, from the same family, like hubs rather than different entities? Maybe they could use these opportunities to improve upon the mechanics of the previous games as well. 

I would love to see something like this for the forza series! Alas, this is not a practice that is popular today. We've seen it with the Master Chief collection and more recently with Hitman 3 (Hitman 2 did the same thing too).