I would state that last paragraph even more strongly: my hypothesis is that the views about EA held by people who will never decide to get into EA will ultimately have a larger effect on how EA impacts the world (both in magnitude and in direction) than the views of people who are already a part of EA communities today.

General-public perception of a group pre-filters the types of people who engage with curiosity toward that group’s ideas, and I think that could be a strong enough force to make my prediction true on its own.  I also think that general public reputation for a group can affect the types of opportunities that the group can access for acting upon their ideas, which might particularly shape the actual activities of a community that largely focuses on each person’s highest impact opportunities.

Interesting — that’s not how I would have read that language.  I would have instead said that this phrase clarifies that the person pledging will repeatedly identify the most effective organizations, rather than just identifying the best organization(s) once at the time of the pledge and then donating to those entities throughout their life.