I think what you are referring to is “whataboutism”, but I don’t think it is a case of whataboutism.
I have pointed out that in a similar case (potentially fake evidence), same actors (journalists) seem to have completely different incentives than those you hold so self-evident and I ask for an explanation of the difference - why is it so self evident that journalists have an incentive to not understand DKIM and not inform about it, but the same is not true of another concurrent challenge to evidence authenticity.
To me it sounds like you’re saying “journalists eat cotton candy because they like sweets, but they don’t like chocolate because they care about their teeth”. They might have this preference among cotton candy and chocolate, but the explanation is inconsistent and likely wrong.
Regardless, the fact that deep-fakes exist has absolutely no impact on whether DKIM has problems or not.