It wont make sense to a general audience probably, which doesn't help when attempting get people to understand things better. If used in the right context, like if you say "people of color, the global majority" it could work well. I just feel like if when talking to regular people it's best to do the least amount of explaining unless they ask you to, people's eyes glaze over pretty quick if someone they don't know well is trying to explain something and they're not completely vested in the conversation. If someone just says "global majority" expecting someone to know right away they mean people of color, the point might not be conveyed as well