I really don't want to talk with them. Is there a chance I'll be announced as "no longer one of..." after he's left if I don't?
I think you shouldn't either way. The WT has no power or authority over you. None.By now I'm quite sure you have to be aware that their efforts to reach out to you have nothing to do with your well being. They may just want to check the box, or as many of them, they just want to have the last saying. They hate hate hate people leaving and cutting ties with them in their own terms.
Well, that is the rational part. However, I'd like to ask you, do you feel that there are unfinished business between you and them? I ask because on one hand you are not answering the door, but on the other you are mentioning things you'd like to tell them.
I know that as we build confidence and a life outside the WT we become less and less interested in whatever they have to say, so I guess I'm asking where do you feel you are in relationship to them as of now? I think that matters since the degree of attachment (or detachment) does affect your reaction to them.