What Piers Morgan and others like him in mainstream media need to learn is that simply saying you support trans people and trans rights is valueless unless you incorporate those values into your show when you have trans people on as guests and when you discuss us on your shows. To demonstrate support, you must also demonstrate respect, and one of the easiest and surest ways to do that is to refrain from referring to a trans woman as a man, former or otherwise, for any reason, ever.
Whether Morgan or anyone else believes it’s accurate or not is irrelevant. What matters is that trans women perceive being described as former men as disrespectful, demeaning, and rude. In the end, if Piers Morgan is truly the trans supporter he says he is, then what he thinks really shouldn’t matter. Simply the fact that Janet and other trans women were offended should be enough for Piers Morgan to apologize, learn from his mistake, and promise not to repeat it.