Not a good day.
If he is dropping the libel suit, it implies that the accusations were true and now NY has the evidence.
I understand why you would say that, but its not necessarily true. Everything in the reports could be false and Cohen could still lose his libel claim.
I think it's simply a matter of him now knowing that he's under criminal investigation. If he keeps the civil cases going, he will have to give testimony under oath; his criminal lawyer probably advised him to avoid any discovery until the criminal case is over.