You're only bound by the terms of OpenAI's agreement if you agreed to the terms of use. If a third party obtained the data without signing an agreement with Ope

You're only bound by the terms of OpenAI's agreement if you agreed to the terms of use. If a third party obtained the data without signing an agreement with OpenAI (eg. by just downloading it from that repo) they are under no obligation to refrain from using it to compete with OpenAI. It is fair-use by the same argument OpenAI itself uses to train its own models on publicly available data.