I think an inportant change to the OP question would be asking when the last recorded prophecy of a larger world even to occur. While there were a few BOM prophets who prophecied of events that occured prior to the 1830's and there is a thinly provable prophecy about Joseph Smith predicting the start of the Civil War. I don't know if there has been since then a single reported instance of a prophet prophefising (sorry, is that even a word?) about anything in the latter 19th, 20th, or 21st century.
I wonder why WW1, WW2, Any number of wars since then, or any number of world events were not predicted. I wonder why there are no "future" world event that have been prophicied. There have been a couple of temples accidently (or intentionally) destroyed over the years. Why were these not know about? Why is there zero prophecies about 100, 200, 300 years from now? 1000 years from now.
I would tend to say that as far as revelation making it to canon, I would say that the ones mentioned earlier would count, but I'm actually not sure about the Families one. I've always felt that the proclimation on the family was scripture, but not sure if its been voted upon making it full doctrine.
A closer look at the War on Prophecy shows that Joseph Smith not only predicted the Civil War, but also the world wars. I also believe he predicted the collapse of the Soviet Union and the current attacks by the radical Arab world. I recommend my article at the link above.
To note Pres Hinckley's General Conference Priesthood Session warning in 1998 about getting out of debt, and suggesting some very difficult financial times for the world are very relevant today. He stated this when the economy was going through a mild slow down - nothing of today (crash of the Tech stocks in 1999, 9/11, Iraq War, $4 gas, crash of the housing market) was on the radar then.