Is this the first time OpenAI has published comparisons to other labs?

Seems so to me - see GPT-5.4[1] and 5.2[2] announcements.

Might be an tacit admission of being behind.

[1] https://openai.com/index/introducing-gpt-5-4/ [2] https://openai.com/index/introducing-gpt-5-2/