A state party nomination, at a fall convention, would cost valuable weeks of time (presuming the election is held in Novenber).
The stakes are high enough that clowns like B.S. are starting to come out -- it's certainly worth it to convene an August meeting, to officially get the party mobilized in one direction.
I agree it's late.
They'd probably move the date up, but call it the "fall convention" anyway.