I guess I don't understand why it's shady. It seems more like a poorly executed decision to enforce a publicly stated policy (it's been against Anthropic's ToS to use their models on frontier ML research for a while now). After all, people found out about this through their published system card.

It is definitely a bad idea to do this without notifying the user, because users who are incorrectly affected will have no way of providing feedback or getting support. And it is also anticompetitive, but if you truly believe that AI is not a normal technology, it is rational.