This is a nonsense argument. You can't apply the 21st century legal rules of evidence or consent to an ancient biblical story. Nor can you conclude anything based on the limited information available in this story and no opportunity to question any witnesses. Let's hope you don't take this same nonsensical approach in the rest of your life outside this Message Board.
It isn't a non-sense argument at all.
Firstly let's recognise that it is Vlad claiming that the NT account provided evidence for consent - not 1stC consent, but consent. That is why we are discussing it - specifically whether the text in the NT is sufficient to support Vlad's claim that she gave consent - it clearly isn't and the 'power relationship' and servitude elements are red flags that indicate there was no consent (not of course that there is any evidence that what is claimed actually happened).
But actually I don't there has been any meaningful change in what we consider to be consent over the centuries. It is, and always has been a decision made by someone who has the capacity to consent, with knowledge of what that decision is and made voluntarily.
The issue isn't that consent was different centuries ago, but that we had a different view on the importance of consent. The historical shift is that in many cases we used not to give a damn about whether someone consented to a whole range on things, but now we do. We have moved from a position where it was common for decisions to be made on behalf of people (i.e. without consent) to ones where we expect the decision to be taken by the person themselves (i.e. with consent). But the notion of what consent is, is largely unchanged.
So had Vlad claimed that it was all OK because in the 1stC people were pretty relaxed about whether a woman consented to sex or not so why is the NT text any different, then perhaps he'd have a point. But that isn't his claim - his claim is that the NT text is sufficient to conclude that Mary consented - it isn't.