Google has been doing the same thing for longer than Anthropic[0]. To protect their models from distillation attacks, they silently will downgrade the model's performance to essentially poison your training data without your knowledge.
A bit different than Anthropic refusing to assist with any AI development at all, but it's in the same vein and seems not widely known.
edit: reading the whole series of Google's AI Threat Tracker articles also provides some insight into threats Anthropic and others are dealing with
[0] https://cloud.google.com/blog/topics/threat-intelligence/dis...