They're wearing a black shirt because they're bullshitting people into believing they're the next SJ.

To me, that's reading way too much into it. Maybe it's fashion that Steve Jobs started, but maybe it's just a black shirt.

Elizabeth Holmes famously (infamously?) modeled herself on SJ.

I see no reason the others are not doing the same.

If you're going to be a fortune teller at a carnival, buy beaded curtains.

Looking the part is half of actually being the part.

The part is to be innovative and disruptive. Copying someone’s look is the opposite.

Copying the look of an innovative distruptor though

That's not the point - "they're wearing a black t-shirt, therefore they are a business genius" is the dangerous assumption.