It matters a lot.
We were reminded of the prophecy multiple times, even as recently as a couple chapters ago ("Believe in Toki's words"). It is specifically supposed to represent Wano-kuni being genuinely free from Kaido & Orochi and all of the tragedies that the people have suffered.
However, I think the whole "9 shadows = 9 scabbards" stuff is a big red herring. Upon hearing the prophecy for the first time, we were specifically told that Orochi feared that the prophecy referenced the scabbards. It would be incredibly anti-climactic for the 9 shadows to actually end up being the scabbards...and only slightly less anti-climactic if it's just some of the scabbards + Momo, Shinobu & Hiyori LMAO.
It's already weird that the prophecy did not come alongside Luffy's defeat of Kaido to be honest. Considering we got textual clarification surrounding the "powerful pirates leading the new generation" moment on the rooftop (which was Oden's prediction), it would be really weird if we didn't get textual clarification on Toki's prophecy...which is a million times harder to decipher than Oden's very straightforward statement.
If there's no prophecy in 1051, then...well you know the rest