It seems the main focus was cost cutting and latency, so maybe a smaller model, or MoE with more experts? One of the new llmsys im-[also]-a-good-gpt2-chatbots

It seems the main focus was cost cutting and latency, so maybe a smaller model, or MoE with more experts? One of the new llmsys im-[also]-a-good-gpt2-chatbots did do significantly better than GPT-4 on one benchmark, but that might be a snapshot of GPT-5 rather than GPT-4o (deliberate misdirection?), or maybe a synthetic-data-based targeted improvement.