The 2012 Convention was not the first time they have said the org. is our spiritual mother and that the bible diesn't shine forth life-giving truths by itself:
57W 5/1 pg 274:
Because they do not also have the teaching or law of the mother, which is light. Jehovah God has provided his holy written Word for all mankind and it contains all the information that is needed for men in taking a course leading to life. But God has not arranged for that Word to speak independently or to shine forth life-giving truths by itself. His Word says: “Light is sown for the righteous.” (Ps. 97:11) It is through his organization that God provides this light that the proverb says is the teaching or law of the mother. If we are to walk in the light of truth we must recognize not only Jehovah God as our Father but his organization as our mother.