Announcing one's goals to the general public is harmful. But how about having a group of people with similar goals -- would sharing the goals inside the group harm too?

(My model here is based on human as a social animal. Scenario 1: You announce your goal. Others mostly ignore you; or give you token support, which you feel is not genuine. You get a feedback that your goal is not important for the group, so your brain lowers the goal priority. Scenario 2: You announce your goal in a supportive group; you get a feedback that the goal is important for the group; your brain raises the goal priority.)