Dumping will definitely happen, but if the strongly supported coins and developers are persistent in continuing to increase the tokens they issue, the demand and supply will at least be well linked. So if the relation doesn't go well then it'll just keep the price dropping without high demand, the token won't be able to have a worthy value and that's become a concern so far.
The problem is that the tokens are not blocked at least until they reach the first planned point from the roadmap. In the current market situation, investors do not buy tokens until they make sure that developers will fulfill their promises, so even a small amount of tokens is enough to significantly reduce the price, because there is deficit of buyers. I think the most important thing is to plan the allocation of tokens for marketing at the time of ICO and block them for a certain period of time.