I agree that the bounties will be ended because it is the way of advertisement of the company. I also think that limiting the participants is a good thing because to be fair with the reward of the bounty hunter, also there are many bounties to join with.
So how will ICOs promote their projects if not by bounty hunting then? Bounty hunter system is one of the cheapest mechanism in promoting projects, at the same time it strengthens the community that supports by pooling in hunter together.
So I believe that bounty hunting will not end soon or way in the future, whenever advertising is present, so is bounty hunting.