WTO rules that US tariffs on China violate trade rules
WTO decides against the US
It isn't a big surprise that the WTO panel has decided against US tariffs on Chinese goods.
The panel has said the US has not met the burden of demonstrating that the measures against China are "provisionally justified". They recommended the US bring the measures into conformity.
The WTO appeals panel is broken at the moment because the US has refused to appoint anyone to it.
I wouldn't pin the reversal in FX moves on this announcement but I would note that FX has tended to lead equity markets lately, so watch out for a retracement in US stocks.