exactly, it works like a wing. big surface and air going underneath and is guided by the shape downwards.
When you compare CRF and SWM front fender you will see that the SWM fender is much wider and catches more air.

The faster you go the more buoyance. Hold out your hand off a car window.
Turn it horizontal and after 45 degree upward and you feel how your hand is pushed upwards.

Barry mentioned to me a rear suspension adjustment might help to a certain level.
Harder spring keeps the rear end up.