So, the fact that Luffys fruit seems to be special, but literaly no one mentioned that before (not even Shanks, Whitebeard, Mingo, Kaido, Linlin) or even recognized the DF as something special, brings me to the conclusion that it somehow needs to be connected to the history from 1000 years ago. Something which isnt necessary part of the known stuff, maybe even for rayleigh. But the government, or at least Imu remembers. So i think it is not necessary a DF with unrelated powers and stronger then everything else, but like a bad memory of Imu, like the straw hat.
Means, not special in power or relevance for the upcoming events, but more like reappearing symbol.