Sounds like a good idea. Will put a stop on scam project who wish to run bounty just to run away with money. When they have something at stake, here money for instance in escrow. Less scam projects would go ahead with bounty.
That is why all respected managers supervising companies with payment at BTC work only through escrow, with very few exceptions, such as best changer.
But even if the developers of new projects will allocate part of their tokens as a guarantee, it still does not give the employee any guarantees, because tokens can become garbage after entering the market.