Only 2 of 21 AI Providers Publish the EU AI Act Training-Data Summary

A census of 21 major GPAI providers found only DeepSeek and Mistral publish a dedicated "Public Summary of Training Content" matching the AI Office template. The other 19, including OpenAI, Google, Meta and Anthropic, cover training data only briefly in model or system cards.

• DeepSeek and Mistral are the only providers with a dedicated template-shaped summary
• OpenAI's GPT-6.1 Sol card spends one sentence on training data
• Anthropic's 149-page Claude Sonnet 4.5 card has just two paragraphs on data
• Article 53(1)(d) of the EU AI Act has applied since 2 August 2025