It does and it does not, what makes the market value of ethereum grows is when people add money to their ethereum wallet, and since purchasing new token requires that they fund their ethereum wallet which they will transfer to the project developer, at that point they deposit fiat and change to ethereum, it will definitely add up to the value of ethereum.

The reason why its effect will later be reduced is because the ethereum was deposited for a purpose, it is just like paying salary with it, ethereum deposit for salary purpose will not stay long in the market, so as ethereum deposited for the development of project will not stay long in the market too.

Project developers must definitely cash it out in fiat to carry out the project, if the entire project that had carried out their ICO through Ethereum had left their money in the wallet, the value of ethereum would have probably reached ~$2000 by now.