I think we have far too far to go in advancing trans* rights before we can go about reclaiming that word.
Language shapes how we think about things, and how others think of us. It's NOT just "semantics."
Oh, for what it's worth, this is NOT a semantic debate: it's a pragmatics and normativity debate. We know precisely what tr*nny means (semantics); the debate is over whether there are bad effects to its use (pragmatics), and whether one ought to say it, or whether one is permitted in saying it, normatively speaking (normativity).