Microsoft is hiring nuclear scientists presumably to power AI. If this becomes the case, I don't think it will be the case that Microsoft's green energy use is just pushing people to use dirty energy elsewhere. If anything they would be helping to accelerate a green transition.

I don't see what's happening now as "Green" but I don't think you need 100% renewables worldwide for a datacenter to be green. You could also build a datacenter by a Dam which is in a location where people wouldn't normally live. This is not all zero sum.