They wanted low noses to try to avoid cars riding up quite so much during contact. So they said the tip of the nose had to be a certain max height, with a certain maximum cross section.
But that's not good for the aero, and the loophole is to have a penis nose for a while to satisfy the regs with minimum aero impact, and then a conventional high nose to get as much air under the tub and around the sidepods to the rear.
It's no so much that they told teams to do this explicitly, but more that they didn't see the impact of what WASN'T regulated.