I worked at one of the big ones and we always shipped live to all consumer devices at the same time. But this was for a popular suite of products that generate

I worked at one of the big ones and we always shipped live to all consumer devices at the same time. But this was for a popular suite of products that generate a lot of consumer demand, so we had a rigorous QA process to make sure this wouldn't be a problem. As I was typing this, it occurred to me that zero people would have cared if this update was staggered making it pretty silly not to.