Well "DEI vetos it" is obviously a problem. There's a discussion to be had around expanding candidate pools, expanding the pipeline, however you want to phrase it. These are good and noble goals but we're not talking about the pipeline we're talking about the candidates for a given role that we're hiring for right now.
No department should be vetoing any hire in a different department. Having an engineer veto a hire in the DEI department is ludicrous on its face, but no more ludicrous than having a DEI department tell the engineering team they're not "allowed" to hire a qualified applicant because of their race or gender.
It's HR's entire job to set policies for hiring. They can say a candidate has to have a college degree. Why wouldn't they have the right to set this policy as well?
Protected class cannot be used as a factor in hiring. Saying "we can't proceed with an offer until we've hired at least one woman and one URM" (which is what Meta's DSA entailed) is indeed using protected class as a factor in hiring.
No department should be vetoing any hire in a different department. Having an engineer veto a hire in the DEI department is ludicrous on its face, but no more ludicrous than having a DEI department tell the engineering team they're not "allowed" to hire a qualified applicant because of their race or gender.