This is an epistemologically flawed political project. First they denounce Orientalism: there's no Other, we're all same humans. But then they say but The Global South is different and cannot be understood by outsiders. So essentially, it's self-Orientalisation now re-branded in the Global South packaging. If you push for universalism, stay consistent at least about the basics and think through how you are going to resolve your logical fallacies.
Besides, any theory without empirical evidence is unfalsifiable arm-chair pontification. It cannot be proved neither right, nor wrong:and hence has nothing to do with science. Theory need to be grounded on studying a particular object by applying a particular method to it. Both the object and the method should be laid open and clear for critical scrutiny. When the object is something as vague as "culture" (in fact, ANYTHING) and the only method is Homi Bhabha-style projectile verbal vomiting, the critical scrutiny is but one likely guess against another, and the resulting theory is not worth the paper its written on.