[citation required]no other prior rumors
You link to a report from 5 days prior to the September launch event. Bloomberg broke the iWatch news back in 2013.
https://www.macrumors.com/2013/02/1...0-product-designers-working-on-a-smart-watch/
From your link: "Echoing earlier reports, Kuo believes Apple will unveil the iWatch at its upcoming September event, with sales starting in 2015. "
Also: "We expect casing material to be of 2-4 different types . . . iWatch will be rectangular in front/ panel side shape."
Again, blindingly obvious. And like Nostradamus, vague enough to be "right" even when he isn't.