No, I can't think of any AAA games that have intentionally released their code open source (unless it's years and years after the game has been released, like Quake, for example). They usually only add mod support. Probably the closest thing to a AAA game where the source code was fully available was Minecraft, but that's because it was originally written in Java and thus easily reverse-engineered.
2048 and Flappy Bird were to demonstrate the cloning problem that App stores have been dealing with, in part because of how simple those games were to recreate, but also in part because it was made even simpler because the code was easily available.
For an example of something closer to the problem that AAA would face if they made their code open, look to the shitshow that Steam Greenlight faced that Valve had to put a stop to. People were downloading some Unity assets and slapping together total broken crap as fast as they could and selling them as full games. That's the type of thing you could expect if AAA was more open with its code.
2048 and Flappy Bird were to demonstrate the cloning problem that App stores have been dealing with, in part because of how simple those games were to recreate, but also in part because it was made even simpler because the code was easily available.
For an example of something closer to the problem that AAA would face if they made their code open, look to the shitshow that Steam Greenlight faced that Valve had to put a stop to. People were downloading some Unity assets and slapping together total broken crap as fast as they could and selling them as full games. That's the type of thing you could expect if AAA was more open with its code.