I don't think so that google will also ban ico marketing. If this will also happen then there will be no more credibility to ICO's and this will have a good effect to those who are planning to create their own ICO. I know that google has a lot of ads but this will also reduce their charts(sales).
Not that really will affect the investors but the ICO advertisers are the ones to be directly affected but there are still a lot of way to promote their ads.