personally I believe they will not because there an IEO already but I like to hear yours.
Very interesting question.
My answer would be no, in general. People have seen enough of ICOs to realize that the majority of them are simply ploys to make money for the founders and once they do, the founders will abandon the project one way or another and move onto the next one potentially even under a different name.
That said, there is potential for ICOs in the form of angel investments to thrive in 2020 with the institutional space more mature and willing to invest. However, the criteria is obviously much higher and genuine development needs to be seen for anyone to be willing to invest. It won't be as easy as 2017.
People will invest when projects are obviously up and running. One example of this is the Telegram ICO which they gathered about $1.7B. You may not see another project that will collect that much during ICO but probably if big companies are going to release a token. DAICOs would probably be the future when it comes to team asking for fundings, Vitalik explained it here https://ethresear.ch/t/explanation-of-daicos/465