Illustration: Lindsey Bailey/AxiosA wave of top OpenAI executives — including Sam Altman's top deputy, a longtime chief operating officer and the chief revenue officer — has left in the span of a month as the company retools its leadership ahead of an expected IPO.Why it matters: Co-founder Greg Brockman is getting more involved across every level of the company to build out a leadership team he hopes will catapult OpenAI past Anthropic in enterprise adoption, according to a source familiar with...