Cars with HIDs should have self leveling sensors on the suspension and headlight washers.
If your car has HIDs and none of the other 2 items it will fail. There is also the question of beam pattern.
However, the MOT test can only be issued on the day the car is inspected, and I guess there is nothing stopping people fitting std bulbs for the test.
....I can see the police dishing out quite a few correction notices after the new regs are included in the test...
What If There Were No Hypothetical Questions?