Computer generated content has its place, as it already does in many procedurally generated games as others have pointed out but I do not think it will play a central role in the near future.

One reason for this is technical. AI (not AGI but the systems that actually exist) can synthesize existing game data into new things but you'll still be in an uncanny valley of recycled information and in the worst case be in some bizarre feedback loop of old content that is permanently recycled and reconfigured in ways that players will notice. No Man's Sky is an example.

The other reason is social, and I think it's the stronger case. We already have many games were computers could replace humans, chess is the most obvious one. Yet computer chess competitions only create marginal interest (by AI engineers) and players vastly prefer human interaction for the sole reason that it is human interaction. In the same vein there is computer generated music that actually is good enough to fool people, but there doesn't seem to be any market for synthetic artists.

Or take Esports. Deepmind's AI systems are actually good enough to produce Starcraft tournaments solely played by machines. The games even look like high level human gameplay. But there is zero interest in watching a bot tournament.