These are huge losses. Pachocki led pre-training for GPT-4, and probably GPT-5. Brockman is the major engineer responsible for the efficiency improvements that enabled ChatGPT and GPT-4 to be even remotely cost-effective. That is a piece that is often overlooked, but OpenAI's advantage over the competition in compute efficiency is probably even larger than the model itself.
As a part of this transition, Greg Brockman will be stepping down as chairman
of the board and will remain in his role at the company, reporting to the CEO.