I do not know AcoA literature, I do not know how the understand this.
I think some people tend to retract from the world when under pressure, it is a tendency I am aware of when it comes to my self.
I am not sure it is always motivated by trying to hide something. Some people will gain energy by interacting with others and become frustrated when alone, others will become exhausted by interacting with others and need to recharge alone.
But if you are always seeking isolation something is wrong and you need to addresses that – but I would see it as wrong to pressure introvert persons to share if they find that difficult.
People are different – that is a reality we just need to accept.