There is a fundamental difference between the executive branch "requesting" information and the judicial branch issuing a warrant/subpoena. In the former, it is perfectly legal for Apple to say piss off. In the latter, it is absolutely not.
The US Government issues National Security Letters to every tech company operating in the United States, and it is legally mandated that companies comply with these subpoenas. So if Apple or Microsoft receive an NSL, the US Government is going to get your information. This includes anything you've uploaded to iCloud and anything in your Microsoft account/OneDrive/Bitlocker recovery keys/etc.
American presidents are not dictators. The system has checks and balances and the courts decide. It doesn’t matter who the president is.