HO CHI MINH CITY — ChatGPT creator OpenAI is rethinking its hybrid profit-and-nonprofit corporate structure, CEO Sam Altman said at an artificial intelligence event in Vietnam just weeks after his sudden ouster and return as head of the company.

In one of his first public appearances since the dramatic events last month, Altman told an audience on Wednesday that his ouster had been “shocking” but rebuffed a question about a secret artificial intelligence project reportedly linked to the board’s decision to remove him.