It is possible the DoD might later give them the same ultimatum that they gave Anthropic, especially if the fallout of that breakup turns out to be as bad as they are threatening (which remains to be seen, of course).

Also possible that OpenAI expects this outcome and has decided that when/if that happens they can claim their hands are tied and they have to agree because it would be fiduciarily irresponsible to suffer the same fate as Anthropic.

Obviously this is all baseless speculation on my part.