According to the LDS, why is there large amounts of new revelation if Jesus is the fulfillment?

Matthew 5:17-18 says: >17 “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. 18 For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished. It seems to me that the LDS tradition includes so much new revelation (ex: God as a created being). How is this necessary if Jesus is the fulfillment of the Law? Is this new revelation fulfilling something? **Additional Note** If it’s unclear what I’m asking, look at it this way: The law of the Old Testament, especially when it comes to sacrifice, is fulfilled in Jesus Christ. On the other hand, in the LDS faith, the new revelation given to Joseph Smith doesn’t seem to fulfill anything. In fact, it seems like a total upheaval of Christian Orthodoxy. What’s the reason behind this difference?