To play devil's advocate: If they can be compelled to produce de-novo firmware for the purpose of data extraction they could also be compelled to design the means necessary to extract the data from the secure enclave, e.g. by prying the chips open and putting it under a scanning tunneling microscope.
The packages on those chips are usually designed to be melded to the underlying structures enough that opening them destroys the keys they're attempting to hide.
Some people trot the argument that it's OK for the government to compel apple to deliver the backdoored firmware because the measures it would circumvent are not of cryptographic/information-theoretical nature.
Then one could expand that argument by saying that compelling physical reverse-engineering is also OK because the devices are not built to be physically impossible (read: laws of nature) to pry open.
