OpenAI drama: Should the company's board consult with investors about the CEO's dismissal?

  No. OpenAI is a for-profit division managed by a not-for-profit company.This not-for-profit company manages OpenAI's board. Only because of this, the company's board may not discuss with the investors about the CEO's dismissal. Those who invest in the OpenAI  for-profit arm, get some profit, but the most important part of the profit is invested back into OpenAI.