Actually it does matter what the boundary change is. The most common change people distress about is when the therapist decides to limit outside contact via e-mail, phone, or texting. No doubt that's what most of the posters assumed--not to say they would have changed their advice. But if the behavior was outside the bounds of what is considered normal or even ethical for a therapist, then the boundary change assumes different proportions. Also, that blocking an entire topic would have graver implications for the health of the relationship than a communications change seems obvious to me, no matter how much the client felt he needed the emails, etc.