The term "forward growth" I find has been misapplied online. 

Prognathism is a condition whereby the mandible protrudes unnaturally and the gonial angle is very high. This is also known as a downward grown face (one type of it). 

Famous examples of prognathism are Jay Leno (extreme) and Quentin Tarantino (not as extreme but definitely visible).

Now, I want to point something out. Prognathism is not something anyone is born with. If you look at profiles of infants they are all the same. They are all orthognathic and flat. Orthognathism (a neotenous trait) is caused by a healthy maxilla placement and development. Conditions like forward head posture can cause prognathism as the head position causes the maxilla to be pulled down by gravity. This tips the teeth forward which then causes the mandible to come forward and the gonial angle to increase. So in other words, prognathism isn't forward growth at all but downward positioning of the maxilla that tips the teeth and makes the mandible jut unnaturally. The term "maxillary" prognathism is itself a misnomer because the maxilla is collapsed but the TEETH are what is flared.

People with prognathism have weak eye support (sometimes eyes look like they bulge) and weak cheekbone projection. In many cases if the person has improper swallow, bimax occurs with this prognathism and then the chin becomes weak. Some populations in developing countries have conditions like this commonly depending on where you go. But notice "prevalent" doesn't mean "ideal" the same way Europeans have narrow palates on average (cfd manifested differently).

I think in many populations this manifests itself due to lack of nutrients which then make bone development not ideal and thus make proper posture hard to maintain. Cfd manifests itself differently in people but there is no reason to believe prognathism is "genetic" or even ideal maxillary development. It is the opposite. 

Just remember nobody is born with prognathism so that should tell you something. All infants are orthognathic and have flat profiles. Humans being neotenous primates therefore should be orthognathic but positioning and nutrition causes some faces to degrade this way. Also, it is entirely possible to have an ideal palate width, a strong jaw, and still have prognathism simply due to improper positioning. Cfd is never one size fits all