Bounty payments do not have any big influence on the project. Only ICOs with a very weak team management, can allow a price drop after exchange listing. There were so much examples of hunters getting real money, without any price drops after the listing.
In addition to what you said, I don't any reason why 7% which was the highest allocated token pay for bounty hunters this days will affect the price of a project after exchange listing but what most project owners ignore is that what usually lead to the dump in price of project after exchange listing are causes by the early miners.
Like you said only ICOs with weak team management are the project that usually dump in price after exchange listing.