If the big tech companies apply human review to takedown requests against major media clients - I have no idea if they do despite having previously worked for one of them in an entirely unrelated role - they may have concluded that the posted leaked document was non-infringing fair use under the law.
Of course, they could be right or wrong, but you’re allowed to sue them in order for a court to decide that question if they decline to take it down. The takedown procedure is not legally mandatory, although the DMCA safe harbor limiting service provider liability does not apply without it.
I’m not a lawyer and am just discussing here for general information purposes rather than legal advice, so double check this with your own lawyer before filing any such lawsuit. But I am far more familiar with this area of law than most non-lawyers, for various reasons.