OK, well ... there it is, in his own words. Suddenly it's not just about Pride and QuAIA, but about abortion as well. You would think a guy with his credentials would understand something about "connotation," not to mention implicit assumptions in the words we choose. But we can't assume, so let's unpack.
Anti-abortion and anti-choice activists like to characterize themselves as "pro-life" for a very simple reason: it allows them to cast their opponents as "anti-life" and thus claim the moral high ground. It's for that reason that standing up for reproductive autonomy is cast as "pro-choice;" we can't assume that any time a woman wants to terminate an unwanted pregnancy, it's because she wants to end a life -- and indeed, to even discuss it in those terms is to concede the discursive turf to those who want to endow unborn fetuses with human rights. We all know where that road goes, but for the purposes of this discussion, it's important to note not only that, but the effect that choosing those words has on the subsequent debate: it prejudices the whole discussion. If you concede that going in, you've lost before the conversation even starts.
Accuracy and fairness demand, therefore, that defending women's right to choose be described as "pro-choice." That's not a question of taking sides. It's a question of characterizing positions accurately so that whatever discussion takes place (and that leaves aside the whole matter of just how offensive any suggestion that the debate needs to be re-opened is) can do so in a rational atmosphere, as opposed to one that's susceptible to emotional hijacking.
Words matter. Definitions matter. Connotations matter. That's why it's so important to ensure that they're used correctly, and that the emotional and ideological assumptions implicit in the choice of certain words and not others is identified.
There's nothing new or complicated about any of this -- it's Semantics 101. And as noted earlier, a guy with Adam's credentials ought to know this, so one has to wonder what he's trying to accomplish here. Back to the Tweeter ...