If they're truly principled, and these are true red lines, given no other recourse, I would be impressed if Anthropic decided to shut down the company. Won't happen, but I would be smashing that F key if they did.
The other two definitely never would in a million years.
Anthropic have a pretty progressive corporate governance structure, so there is a good argument that they will stay true to their principles. However, this will likely be the biggest test for how strong that governance structure is up to now.
If I had decision input at Anthropic I'd be giving serious consideration to reincorporating in the EU or Japan, and also doubling or tripling my personal legal and security budget.