I think marriage counselors, like judges and divorce lawyers and court officers, have seen every conceivable combination of varieties of truth or untruth and examples of bad and good behavior. The fact that your husband already wrote to the counselor even before the first visit sounds to me (and possibly to the counselor) a red flag: a sign of a controlling and manipulative person.

As an aside, my understanding is that “stbx” means “soon-to-be-ex”—are you keen to have the counseling help with your marriage or are you sort of done and want out?