Remember that it took Ikeda over TWO YEARS to solidify his control over the Soka Gakkai enough that he was able to seize the Presidency for himself.

During that time, observers concluded that the Soka Gakkai would be fine running itself via a board of directors after Toda's death:

After Toda's death there was speculation that the charismatic leadership of Toda had been the key to the Gakkai organization, and that the movement would soon begin to crumble. The speculators were to have second thoughts, for Soka Gakkai not only did not fall apart, but it nearly doubled its membership in the next two years despite the fact that it had no formal leader.

Since Toda's death in 1958 the organization has been run by an apparently harmonious collective leadership by the board of directors with Koizumi Takashi as Secretary-General. – Charles D. Sheldon, "Religion in Politics in Japan: The Soka Gakkai" in Pacific Affairs Vol. 33, No. 4 (Dec., 1960), p. 385 Source

So don't expect a quick solution to the Soka Gakkai's power vacuum.