I don’t see it. You view Paulsen’s position as a “rejection of the idea that God the Father had a father who then had a father and so on ad infinitum,” but nothing in the excerpts you have quoted seems inconsistent with that notion. Perhaps you are resting on this statement: “There is only one … fount of divinity.” Obviously, Paulsen is attempting to respond to the idea that Mormons are polytheistic — a most grievous sin in the eyes of some so-called Christians. But whether God the Father is Himself part of a larger plan does not seem to be addressed at all by this statement. For our purposes, He is the sole “fount of divinity.” If there are other founts of divinity for other people not within our realm is irrelevant to me, which is why, I suppose, we do not have more information about that possibility.
“The Father is the deity subsisting in the prime, unoriginated and most absolute manner, or the deity in its direct existence. The Son is the deity [eternally] generated by God’s understanding, or having an idea of Himself and subsisting in that idea. The Holy Ghost is the deity subsisting in act, or the divine essence flowing out and breathed forth in God’s infinite love to and delight in Himself. And . . . the whole Divine essence does truly and distinctly subsist both in the Divine idea and Divine love, and that each of them are properly distinct persons.” –Jonathan Edwards
Aaron’s comments show how influenced by Platonism the mainstream view really is. The Father is the One or ultimate ousia of Platonism. The Son is the Nous while the Spirit has elements of both the logos and the worldsoul. Of course there are clear differences where this scheme had to be modified to keep with scripture.
And of course those familiar with my comments elsewhere recognize that I don’t think we ought to throw out all Greek concepts. (And one should note that at the time of the NT the philosophy of the region was primarily materialistic with the Stoics and Epicureans – of interest when considering Mormon views)