Earlier quoted context omitted.
I think it means OSS projects should start unilaterally banning submissions from people working for Anthropic.
Why? What does this have to do with the leak
Being written by a LLM is a signal that the submission is of low effort and therefore probably low quality, which then puts the onus on the people reviewing and reading the submission instead of the original generator of the submission. Hence I would classify it as spam.
Open source communities also have rules against LLM generated contributions, for various moral, ethical, or legal reasons.