How do you know for certain that Satan was not already tagged as a rebellious angel before being cast out?
But was allowed to remain until God did what he did to him in his own time frame.
Satan could have been allowed to do both for a time: go to and fro upon the earth AND appear in a heavenly council. God would have had to allow that. And if God did, then he had a reason for it that WE would not be able to explain. Only God would know. His knowledge is infinite and we are not in possession of but a tiny part of it. Much is not told to us.
Judas Iscariot was already predicted to betray Jesus but was nevertheless allowed to remain as an apostle. Judas then went out and hanged himself.
God has a sense of timing. He sometimes strikes people dead on the spot and sometimes allows their evil to come to fruition over time.
God knew Jesus was coming to earth and would preach, minister and die to be raised to life.
He knew it from before the beginning of time, but in earthly years look how long he took to work it out.
Never try to force God into a box that we have created that we think fits God.
The order in which events appear to happen in scripture does not always have to reflect their timing in God’s terms. To God, a day is as a thousand years and a thousand years is as a day.
Or, it could have been timed as it appears to us, that first Satan was cast out, then returned during Job’s story. But again, if God allowed him to appear after casting him out, it was a one time event to make a point, and it was at God’s allowance, not a privilege that Satan still possessed.
I am not sure but I vaguely recall a minister stating after Satan brief visit to Heaven regarding Job, Noah’s Flood occur. Flushing out the stench that Satan permeated in the Heavens.