Not all downforce is lost in the turbulence of another car. If this were true most cars would just run off the road as soon as they catch up with another car and back markers would become an insurmountable problem regardless of the size of the blue flags. On the other hand, the loss is more than enough to make overtaking impossible. On the family car this is roughly 4 to 6 inches but as the F1 car is around two inches off the ground it has to be less than that. The only compromise is to use some of the travel at low speeds for mechanical grip and stiffen up fast so that there is still some mechanical grip left at high speed.
Aerodynamic grip becomes more important and at high speed dominates the roadholding of the car.
They changed the technical regulations. If nothing else changes that will reduce the effect of the front wings. Because the front wings will provide less downforce an equivalent reduction in rear wing downforce will have to be effected by the teams to maintain the balance of the car. A higher front wing should also be less sensitive to turbulence. I suspect that they will all go back to the wind tunnel to figure out how to achieve the same effect with a wing that is two inches higher.