You are absolutely right -- in the sense that even a dead-simple Turing machine built inside one of those other games is Turing complete too.
0x10c feels like a milestone, though... I guess it's because the in-game CPU this time around is usable on a human timescale. If in-game networking is ever added to 0x10c, one could even imagine a usable minecraft clone inside the game. It feels different this time.
Yes, I think it's an important milestone in terms of making that sort of mechanic more available to everyone. Most people were building small, special purpose circuits instead of general purpose devices, simply because it was difficult and wasteful to build your own CPU... unless that was their goal in the first place.
I agree that 0x10^c will likely be something special.
0x10c feels like a milestone, though... I guess it's because the in-game CPU this time around is usable on a human timescale. If in-game networking is ever added to 0x10c, one could even imagine a usable minecraft clone inside the game. It feels different this time.