Trans advocacy is a policy game at every level, not a numbers game. At the national level for example, the UN universal periodic review began recently including trans rights in its methodology. It is far more likely Mattel would respond to this kind of pressure from some kind of industry group than any expectation of high sales (although given a decade of this kind of influence organic sales will be a natural consequence, which is why advocacy efforts are so important to watch to understand the future of society)