I'm just being a North. WAR is a skill; it is repeatable year to year, and you'd expect a 4 WAR guy to be in the general area of 4 WAR next year. Or else it'd be useless. However it's only describing what has happened obviously. So it has predictive value but the intent of the stat is not to predict.
Like FIP. FIP is meant to be a better way to evaluate pitchers than ERA, but is actually a better predictor of ERA as well despite that not being the intention. Has predictive value but is not a predictive stat.
North'd