I mean, gosh, he probably wasn't really DMed, was he? Is he prominent in the larger trader/Wall Street space or something that would warrant such contact?

If it is bullshit and a photoshop, him deleting his whole account speaks potential volumes about a potential eureka moment or realization or moral quandary or something. My guess is this was his way of walking away with some (tiny amount of) dignity and telling his handlers he's out.