I know that this does you no good in the short term, but I assume that you will be eligible for a Pennsylvania license once your Illinois FCCL is renewal goes through. The revocation is not from criminal activity on your part, but an administrative action.
Correct. The IL status is the only reason for the revocation.
The sheriff's office isn't tied into the IL system to verify the status. Per PA law, I had to provide them a copy of my currently valid IL CCW prior to it's expiration for the PA LTCF to be valid. The PA LTCF is issue on 2 conditions (as an out of state, CCW permit holder): 1. Your home state's license is current, 2. PA sheriff's background check is clear.
From the text of the letter, by my interpretation, the same sheriff's office will re-issue:
"If you are awaiting your renewed Illinois Handgun Permit, you are still required to surrender your LTCF to our office. If your Illinois Handgun Permit is renewed in the future, please provide our office with updated copies of both your Illinois Driver's License and Illinois Handgun Permit so that our office can reinstate your Pennsylvania LTCF."