With or without celebrity involved in an ICO, if the managing team behind knows how to market their own project no doubt it will easily funded. Previous ICOs like Tezos, NEO and OmiseGO were never endorsed by any celebrity but all them have a very successful crowdfunding campaign.
Celebrities involved in an ICO are a plus.
However, this is better than without any celebrities involved.
celebrities just bring in speculative short term investors, not real investors that hodl