Of note, there’s no sources to this. To an extent, this is to be expected. Hersh does happen to have a history of breaking a few important stories, but previous stories were backed up by a lot more paperwork than this particular story has.
It should be also noted that Hersh has based this article into single anonymous source, like many times before. He has also spread downright conspiratorial claims before: https://www.vox.com/2015/12/21/10634002/seymour-hersh-syria-joint-chiefs
Winning Pulitzer in the 60s-70s doesn’t mean that the guy doesn’t weer into the deep end of conspiracy theories. Hersh also has also written favourably about Putin and Assad. According to him, Assad didn’t use chemical weapons, and Osama bin Laden wasn’t responsible for 9/11.
Thank you for adding the additional context, hopefully it can help people calibrate how much they should believe this writing.