I agree that LDS make a larger emphasis on Exaltation/Theosis by making it more universal, but it is not unique to them. I maybe mistaken about Greek Orthodox, but in terms of Theosis and Eastern Christology, it is a doctrine and it was touched on by some of the founding fathers of Christianity.
Don’t want to overload the discussion, but here is such an example.
St. Athanasius of Alexandria wrote, “God became man so that man might become god.” [the second god is always lowercase] (On the Incarnation 54:3, PG 25:192B). His statement is an apt description of the doctrine. What would otherwise seem absurdthat fallen, sinful man may become holy as God is holyhas been made possible through Jesus Christ, who is God incarnate. Naturally, the crucial Christian assertion, that God is One, sets an absolute limit on the meaning of theosis: it is not possible for any created being to become (ontologically) God, or even part of God (the henosis of Greek Neoplatonic philosophy).
However note even the simple fact that the second god in St. Athanasius quote is always lower case.
We do not become God's equal, and we certainly do not get our own world and a license to create spirit children.
As with most works of the Fathers of the Church they speak in metaphorical terms, knowing good and well there is only room in the universe for one creator, one deity, one God, as did the people who read their words.