I'm sure she is highly paid, Lizzie but her title sounds to me like a bollocks title for upper middle management PR.
It was a clever move on Twitter's part to put someone in the chair who had no real insight or authority regarding moderation decision-making and could only say 'I'll look into that'. As you point out, it keeps the discussion one step removed. It's known as a good negotiation tactic.
But it is also highly cynical and manipulative on Twitter's part. eg I'm sure it was also quite deliberate that in a discussion about online abuse against women, the person representing the big evil corporation was a young, pretty woman. More easy to look like the big meanie questioning her, isn't it? I'd have had more respect for them if they'd had a scintilla of moral fibre and put a senior (male) exec up there to defend their shitty moderation.
Oh I dunno, I know I'm ranting. It makes me really bloomin' cross. Pathetic, cowardly, big business.