This is stupid.
Since when is filler canon?
And even if it is canon, do you really take someone seriously when they claim someone is 'destroying the universe' when all that is actually shown is a few green clouds and flashes of lightning, and a normal human (Mr. Satan) can stand a few hundred feet away and be completely unharmed?
If L-sama wanted, she could just make it so Buu had no powers and turn him into a mouse. Do you know what 'omnipotent' means?