What Einstein did do for the Atomic Bomb was to co-sign Leo Szilard's letter which got the attention of President Eisenhower and kick-started the Manhattan Project.
It raised a flicker of polite interest that died, from your own link:
The Advisory Committee on Uranium was the beginning of the US government's effort to develop an atomic bomb, but it did not vigorously pursue the development of a weapon.
What did move the needle, again from your link:
The Frisch–Peierls memorandum and the British Maud Reports eventually prompted Roosevelt to authorize a full-scale development effort in January 1942.
In essence, the letter from Einstein did not start the Manhatten Project, it was instead the direct efforts and in person meetings of Oliphant: