The whole article reads as virtue signaling to me. Anthropic already has large defense contracts. Their models are already being used by the military. There's really no statement here.
It's arguable that businesses are subject to the same morality-inducing processes that humans are. For example, as a human (with a soul?) what is at risk when we do something immoral? I see it to be a reputational cost at the highest level. Morality could be viewed from the perspective that it increases predictability/coherence in society (generates less heat).
How is it virtue signalling when sticking by these principles risks their entire business being destroyed by either being declared a supply chain risk or nationalized?