Yes it is new. The WHO only changed their guidance about a year ago [1]. Still, as far as I know the evidence is only associational. From the paper the article links to: "Potential for reverse causality cannot be eliminated".
So it sounds like artificial sugars can actually cause diabetes? That's unfortunate. Occasionally I drink Coke Zero as an alternative to Coke, but perhaps I should start replacing that with unsweetened seltzer water like La Croix.
No, the "Potential for reverse causality cannot be eliminated" means that instead of artificial sweeteners causing diabetes, causality can be reversed: Diabetes causes the intake of artificial sweeteners.
All these studies just show an association, but can not prove the direction of causality. For whatever reason, the idea that diabetic and overweight people deliberately seek out zero sugar sweeteners so that they can enjoy sweetness without making their situation worse just doesn't seem like a plausible explanation to them.
Personally, if you can't definitively prove something is bad for you after 45+ years of research, I just don't care anymore. People can occasionally drink Coke regular without issue, I wouldn't be worried. Most of the time, diabetes is not caused by merely occasional consumption of sugars.