I think the "affect the bite" myth is an excuse made up by breeders to explain bites that went bad. An overbite in this breed is very unusual. As the lower jaw grows for longer than the upper, minor overbites may correct themselves. Underbites typically get worse, or stay the same, and are far more common. Not surprising w/our bulldog heritage. I have yet to see an underbite correct, though a couple people I trust say they've seen 1 or 2.
I've never heard that bad bites were a major issue in breeds like malinios or dutch shepherds, where frequently pups are encouraged to tug.