Each individuals personality make-up is different. The persons family history, emotional stability, traumatic experiences and how they were processed, social supports, education, belief system, etc.; all these things factor in to how an individual will deal with trauma.
Now, having said all this, destructive, thought-reform groups (a.k.a. cults) are by nature trauma producing environments. Perhaps it would be helpful to define trauma. One working definition of trauma is stress out of control; it either becomes unpredictable, overwhelming or prolonged. Also, I believe that it is highly unusual for a person (particularly one who was in a leadership position in a group like TF) to leave a destructive group unscathed; not impossible, just highly unusual. Certainly, the Lord can heal in the emotional realm like in the physical realm, but such is not the rule. Most of the people whom we work with are ones who initially were asymptomatic. Some did not evidence any difficulties for years and years. Others developed coping strategies that masked their difficulty to trust. They lived lives of denial, compartmentalized their trauma, constriction (places they couldn't go, people they couldn't see, things they couldn't think or talk about, etc.), disconnection (disconnected from self, disconnected from real intimacy with others, disconnected from God). These are just some of the ways that former members of destructive groups cope with their traumatic experiences. Again, this is not to say that the Lord cannot heal the emotional, psychological and spiritual trauma that inevitably results from one's involvement in a destructive group.
I have never read any statistic that 75% of people who were deprogrammed from a destructive group were actually traumatized by the deprogramming. First, I personally do not believe in deprogramming because it is unethical and coercive. Second, I do not know anyone who employs this method. Third, not knowing what article you are referring to it could be argued that the process of deprogramming someone from a destructive group, or abruptly exiting them from it, brought to the fore all their trauma. Thus, the ex-member was not traumatized by the process of leaving so abruptly, but by leaving the group without a supportive network in place that understood the nature of trauma. It is hard to know, and it is easy to quote statistics.
Regarding posters on the NDN site, people are all over the map so to speak. Some are raging in their pain; others deny they have any pain or issues. Then, there is everything in between. Some want to deal with spiritual issues; others believe that that is dealing with the devil in Hell. However, to simply rage or live in denial, as good as it may feel in the moment, will bring no lasting healing to the former member of any destructive group. I would contend that just as we heal physically as human beings according to certain biological principals, so we heal emotionally and spiritually as human beings according to certain psychological and spiritual principals.
I pray all goes well for you on your own journey.