Managers are NOT free to choose who to hire. When you get headcount, they tell you to make sure not to sacrifice quality and, also in same breath, they tell you that you have no career paths if you don't make your DEI numbers. If there are no actual competent candidates in your field who also happens to be diverse, what would you do?

Everyone from CEO to line managers in all major big techs are now have DEI target that must be achieved. If it is not then don't bother applying for promos. Most people at L7+ will also see significant cut in bonuses if they don't make DEI targets. Especially at VP level, the cut becomes pretty significant. So, they constantly badger their underlings to make their numbers. There are very specific commitments you must write down in OKRs.

I have seen a situation where a manager literally ignored every single non-diverse resume and did not interviewed single non-diverse candidate because of desperation of not making his numbers. He went out of his way to get person completely stranger to work his team was doing. He finally ended up hiring a person well below expectations and this person now simply hangs out in the team as diversity token. The VP sent email to whole group congratulating in supporting diversity and be inclusive. Everyone got their well deserved bonuses for this magnificent achievement.