My guess is that the restriction originated with pressure from advertisers. It is hard to determine if a user is actually interested in an add if there is an in

My guess is that the restriction originated with pressure from advertisers. It is hard to determine if a user is actually interested in an add if there is an incentive for clicking and watching. I see that you report your advertisers are aware, but if Apple chooses this for the ads they manage then I am not surprised they would enforce it universally so that developers don't move away from iADs.