Now the ouster of Sam Altman as OpenAI CEO seems to indicate that its board intends to pump the brakes and attempt to reach AGI responsibly rather than recklessly.

But nothing about them firing Altman suggests that. They fired him because he (allegedly) lied to the board. There is no way they will pump the brakes on being the most advanced AI company when competition is this fierce.

driver of the lead car

I don't know if this characterization is true. From all that I've read Ilya Sutskever was always the star and most important asset of OpenAI. Altman seemed like the SV money guy. Money should no longer continue to be as big of a problem for OpenAI, although the coup will definitely have spooked investors.

Edit: personally, I'll add that Altman gives me major ick vibes, similar to Musk, although I can't fully justify them. His WorldCoin scammy project convinced me that he was not the person who should be in charge of potentially in charge of advancing is towards AI.

Ilya and Denis Hassabis are more the kind of scientists with the mettle that I would trust more with the responsibility of stewarding proto AGI into existence. They both seem to understand the magnitude of what they are creating.

But when the daredevil driver of the lead car is replaced with a school bus driver who stops for all of the cross-walks will the other cars in the race abandon all caution, knowing that they are no longer only competing for second place?

I can only hope. Plus, the daredevil driver and a bunch of his mechanics are now available for hire by those other cars.