OpenAI CEO Sam Altman announced more departures at the company he leads.Andrew Caballero-Reynolds/AFP/Getty ImagesMira Murati, OpenAI's chief technology officer, earlier announced her departure from the company.Now, CEO Sam Altman revealed two other executives, Barret Zoph and Bob McGrew, are also leaving.Altman also outlined their replacements in a note to staff.Mira Murati announced on Wednesday that she's leaving OpenAI, where she was chief technology officer.