I think frankly OpenCode is delusional to think that Anthropic is actually "concerned" with them in any way. Anthropic's concerns at this point are on the geopolitical level. I doubt stamping out ToS-violating usage of their subscription services is even on executive radar. OpenAI only allows it because it's a cheap PR win and they take those where they can get them.
Opencode is not delusional, it would be delusional to think Anthropic won't after they have already threatened them.