In the last decade the cool thing for a smart kid was to be a New Atheist. EA is an ideological framework that can fit into that slot. That's a big deal and it allows a group of different organisations to come together and profit from each other.

If you look at GiveWell, the idea of actually finding out the evidence of the effect of a donation is new. What's new is the depth towards which GiveWell researched other organisations.

Concerns over wild animal suffering are surprising/new elements of EA but they aren't central to the movement.