If a practitioner is more interested in process than in story, this has a significant impact on requirements around confidentiality. Of course, as with any practitioner, it is important that a practitioner maintains confidentiality around anything disclosed to them by a client.
Having said that, the chances are that beyond the fact the the client is, say, experiencing anxiety, the practitioner will know nothing more than that.
This also has benefit regarding gaining trust. The practitioner doesn’t need to gain the client’s trust for them to be able to reveal their story. They only need sufficient trust as to describe their current experience.