Mueller is doing quite well, despite The Purge's worries. There is no national security protocol to deactivate security clearances as a matter of protocol. Who are these uninformed Trumpers and righties?
Security clearances are keys, allowing the holders to access information that others cannot access. Allowing ex-employees the right to maintain their clearances is akin to allowing ex-bank employees to keep access to the accounts computer. No employee has a right to a security clearance, and obviously no ex-employee has a right to a security clearance.
This whole issue is a whirlwind in a toilet. A lot of noise, but no substance.