That's kind of a weird claim, because other than direct economic and military aid and pro-/anti-government military intervention from superpowers and trade and defense agreements with them, BoP didn't surface any potential drivers of GDP, nor GDP itself, nor any effects of GDP other than stability and geopolitical alignment of the government.
Whatever was going on underneath, BoP was much more of a geopolitical than economic simulation in what was exposed to the player.
I don’t disagree with you, but he made the quote in the context of explaining why he was trying to make a game about indirectly creating outcomes, which in the major revision went multi-polar so that countries had their own tensions between themselves independently of the two major powers.
Whatever was going on underneath, BoP was much more of a geopolitical than economic simulation in what was exposed to the player.