Anybody who has paid close attention to press reports claiming that Michael Cohen, Paul Manafort, and Alan Weisselberg could be the “perfect storm of cooperators” probably already realizes that Special Counsel Robert Mueller and federal prosecutors in the Southern District of New York and New York state investigators are grasping at straws.
They were also attended in part by prosecutors from the US Attorney's Office in the Southern District of New York.
As was widely reported at the time, Cohen struck a deal with prosecutors over the summer that guaranteed him leniency in exchange for his cooperation with federal investigators.
So if ABC's reporting is accurate, these meetings happened over the summer, or even earlier.
…Which means that if Cohen had given investigators anything substantial, that information would have leaked by now.