Microsoft CEO Satya Nadella. Ben Kriemann/Getty; Tyler Le/BI CEO Satya Nadella just dismantled the senior leadership structure that has run Microsoft for decades.It's the latest step in his plan to reboot Microsoft for the AI era and transform the 220,000-person behemoth into a company capable of competing with its smaller, faster, technically sophisticated rivals.Business Insider spoke to people who work closely with the CEO and referenced internal documents to determine who's in, who's out, an...