I can assure you, if the government decides you no longer need your access it is removed immediately regardless of who you are. This should have been done quietly. He will have signed the Official Secrets act, which says in part that he can be prosecuted for any leaks of information he gained while using his clearance.
He didn’t lose his clearance...
all of which is irrelevant...he was put there to do a job, and having completed it, now leaves NSC in the hands of McMaster.
The Director of the National Background Investigations Bureau Charles Phalen has stated: ““The President has the ability to grant a clearance or grant access to anyone whom they please – it is at their discretion”.
You are making the mistake of believing media reports...
How long have you been here?
He was NOT fired or demoted, he essentially CHOSE NOT TO be in this role any more