The war in heaven was the proving grounds for the initial choice of God’s creations. There we were, in effect, free agents. God was our Father and Creator, and He proposed a plan (system) whereby we could all become like Him, if that was what we wanted. Some did not want to follow His system.
There was only one plan on the agenda during the council in heaven as taught in Abraham 3 when Lucifer got his feelings hurt. Notice verse 27 when the Father rhetorically questions, Whom shall I send? In verse 28 Lucifer becomes angry. Up until that time, Jehovah is already creating worlds and organizing universes. There is still no second plan. Lucifer has only lost his temper; he doesn’t formulate his plan, a non-functioning one that cannot exalt, until the next council as found in Moses 4.