We have no evidence he agreed or didn't agree to the wording. A quorum of the board met, probably without the chairman, and voted the CEO of the company and the chairman of the board out. The chairman also happens to have a job as the President of the company. The President role reports to the CEO, not the board. Typically, a BOD would not fire a President, the CEO would. The board's statement said the President would continue reporting to the CEO (now a different person) - clarifying that the dismissal as board chairman was separate from his role as a company employee.
Based on the careful wording of the board's statement as well as Greg's tweet, I suspect he wasn't present at the vote nor would he be eligible to vote regarding his own position as chairman. Following this, the remaining board members convened with their newly appointed CEO and drafted a public statement from the company and board.
> When Altman logged into the meeting, Brockman wrote, the entire OpenAI board was present—except for Brockman. Sutskever informed Altman he was being fired.
> Brockman said that soon after, he had a call with the board, where he was informed that he would be removed from his board position and that Altman had been fired. Then, OpenAI published a blog post sharing the news of Altman’s ouster.