I think you're using the American right wing definition of DEI which describes a bit of a strawman. In reality, a leader establishing a rule that people aren't to be discriminated against based on e.g. race or gender, is an example of a DEI policy.

So when I said anti-DEI is a marker for a specific political ideology, it's really because it's a marker for the kind of media a person consumes, which informs the definition of DEI they're using.