The pilots can appeal the revocation to the NTSB, but most of us here in the US would be amazed if the NTSB were to reverse this revocation. The NTSB can extend leniency if there are major extenuating circumstances. I do not see them in this case. Can anyone else provide an argument for reversing the FAA revocation other than "we are all human" or similar?
As I have said previously, they would have been better off if they had actually fallen asleep. Then they would have faced a license suspension, some sleep apnea testing, and eventual reinstatement.