It certainly would have helped if he'd published it a couple of months ago.
Yes, that would have helped Bernie Sanders, who would be a different candidate. I am guessing, that is not who they wanted to see picked. Even now the Democrats are headed to a technically open/contested convention. If Bernie would drop out (before) the convention, then we might see this kind of release of evidence to, "save the party." Without that concession, you run the risk of all the super delegates switching to Bernie and handing him the nomination. In most things timing is very important, politics is one of those things.