That's because they're completely mixing up the history. They're already hinting at the destruction of Numenor, and they've introduced all the characters involved in that (except Sauron himself), all of which should happen 2000 years after the forging of the rings. And they're even hinting at the dwarfs digging too deep in Khazad-Dum (4000 years in the future).

They're clearly writing a completely new timeline, made up of parts of Tolkien's timeline.

One of my biggest pet peeves in made up fantasy worlds is the fact that their worlds are absolutely static for hundreds or thousands of years at a time. Nations rise and fall constantly! Maps shift! First the kingship is in Eridu, now it's in Bad-Tibira! Then Bad-Tibira fell and the kingship was taken to Larag!

(Of course, this makes the trope I'm complaining about Older Than Dirt, since the Sumerian King List claims their kings ruled for tens of thousands of years)