What Would Happen to the Block Reward If the Difficulty Adjustment Failed to Occur after a Major Hash Rate Increase?

If the difficulty adjustment failed after a major hash rate increase, blocks would be mined much faster than the target 10-minute interval. This would cause the block reward to be issued more frequently, effectively accelerating the issuance schedule of Bitcoin.

The total supply would be mined faster, and the halving events would occur sooner than their four-year schedule.