We know that none of them have accepted Jesus because none of them have been healed, remaining occupied by devils. As explained in The Bible.
The Bible also records what happens when such wretches DO encounter Jesus. First the demons scream and wail. They might show off a bit with a convulsion. Or some headbanging. Sometimes they declare Jesus to be The Holy One or remove their clothes. And if they accept Jesus the demonic yoke is lifted: they are free. The demons are recorded as having different destinations after this and I couldn't care less what happens to them but the point is that if the demoniac REJECTS Jesus they remain DEMON POSSESSED.
The fact of abiding possession tells us that Jesus HAS BEEN REJECTED or perhaps never encountered or even that they have not understood the reality of vicarious sacrifice or the redemptive power of blood which, as we know because Jesus has told us, is something any child would understand:
Luke 18:17 Verily I say unto you, Whosoever shall not receive the kingdom of God as a little child shall in no wise enter therein. KJV