I think they got it wrong.
I think it’s a “arrow” shaft or spear shaft straightener.
Cordage is made by twisting and reverse wrapping with fingers and palms on thighs. One person could make about 20 yards of two ply reverse wrap cordage a day without any tools. Think of kitchen string.
(In the modern world, rope and cordage is twisted on hooks.)
I can’t see how the tool they found could possibly be useful for making rope.
I think the phonies at Science mag are smoking hemp.
King Ludd has spoken.
The first was found many years ago. Back then we made a reproduction model of it and it absolutely makes great rope just as they claim. Just keep twisting and feeding it.
Perhaps it was a multitool!