Due to programming issues with Night Vision granting all moves maxed accuracy in the darkness, it has now been changed to grant a 1.3x accuracy increase similar to Compound Eyes in the darkness. Functionally it's slightly less powerful but still fairly good. Butterfree was useable in Advanced Gen because of 92% accuracy sleep, and the Pokemon with Night Vision have some fairly good stats. Harskrow, for instance, has a 92% Dive Bomb instead of 100%, which is still pretty amazing.

Just letting you know.