Yes, thanks for noting that. While Apple would most likely do everything in their power to unlock the relevant devices, they don't have a known backdoor to the encryption systems (Secure Enclave, FileVault, etc.) that safeguard the data on said devices. As the article itself notes:
"We have great sympathy for surviving family members. Once the court order is received, we will help as much as possible to grant access to the personal information or devices you are requesting. Please note that devices locked with a passcode are protected by passcode encryption, and unless the next of kin knows the device passcode, Apple will not be able to remove the passcode lock on the device without erasing it."
In terms of gaining access to a deceased person's devices, one thing that Apple could do is remove Activation Lock on those devices. That would open access to the devices themselves (it would be usable again after an erase), but unfortunately not the data inside. This is because the Activation Lock system is fully controlled by Apple servers, but the encryption on the devices is not.
EDIT: On a Mac, you'd have to enable FileVault in order to get the same level of protection that you get when setting a passcode on an iOS device. Apple or a third party could reset the login password if FileVault is disabled.