To answer this question I must speak through a very personal point of view.
I believe that true forgiveness comes when a person operates from a point of self-empowerment, when a person can take full responsibility for all the good and bad of their own lives.
Only then can one forgive; because we see that we are the ones in power to change and create what we want in our lives. And once we see and know that, then what others have tried to do to us or whatever has happened to us does not matter anymore. Allowing us to release whatever it was that held us back and ultimately free ourselves.
So my answer to the question is yes, hypnosis can help with forgiveness because we can use different hypnotic exercises to help us empower ourselves. However, there are many other ways in which self-empowerment can be born in a person. Such as a life changing experience or through advanced meditation practices.