Apple has since confirmed in a statement provided to Ars that the US federal government "prohibited" the company "from sharing any information," but now that Wyden has outed the feds, Apple has updated its transparency reporting and will "detail these kinds of requests" in a separate section on push notifications in its next report.
As other commenters have noted, Apple's treatment of Russian and Chinese users should not give you hope for their resisting US federal oversight.
Apple fought back against forced decryption orders. They could theoretically decrypt any iPhone they're given with new firmware but they don't want to.
On the other hand, Google isn't exactly working with the authorities either. They moved Google Maps' location history to on-device storage because of the many warrants they were served, for instance, and they too refuse to decrypt phones.
These companies know to pick their battles, but they did take on the government various times.
> They could theoretically decrypt any iPhone they're given with new firmware but they don't want to.
This is untrue at some technical level: Apple is currently unable to break AES-256.
The San Bernadino case was about having Apple create and sign new firmware that would enable a brute force attack - which could easily be unsuccessful. I don't believe the Secure Enclave found in newer models even allows for a brute force attack (enforcing some delay, among other things) from BFU state.