Ya...I thought it was kind of a funny statement from a professional pilot....... 
We're talking in-game performance. Real life is a different story. In AH, there are many more factors, such as torque modeling, that affect functional climb rates. There's always outliers (e.g. Me 163), but you can hold this true as an overall rule of thumb.
For example, if we're trying to argue that X aircraft gains an overly-generous 800yds (2400ft) altitude difference in zoom climb over Y aircraft, most neglect that 800yds is still well within guns range and you're going to get shot by the guy you're trying to out-zoom climb. And that's an extreme example, most perform well within 1000ft of vertical climb distance of each other.
For all intents and purposes, it doesn't matter much when comparing two aircraft zoom-climbing at the same speed. That is the context of the original statement.
What matters most is low drag / higher aspect wing ratio. This equates to a decent amount of maneuverability, with much less induced drag. This allows the pilot to go from varying climb angles and avoid the opponent climbing to them, while retaining enough E advantage to continue zoom climbing.
