Would be irrelevant, because the DNT-header will be sent with every request, so for all practical purposes will be later than any other kind of consent.
There can be a case where the end user (person), logs on the site - then sets a permission/consent to be 'tracked' (whatever), then a cookie/localstore persists - so the DNT is not relevant.
Consent/tracking doesn't mean solely 'cookie' banners.
