I looked it up, and apprently this could be true, assuming that wikileaks were given the emails ahead of time. Some of those emails were first posted to a DCLeaks website, then Wikileaks announced they'd be posting some, then DCLeaks posted more a few weeks later, then Wikileaks posted some, then Wikileaks posted more just before the election.
It makes sense to time these things for impact, assuming you want to punish corruption, and that's the motivation behind these kinds of leaks, right? People seem to focus on the part Assange and the Russians played in this instead of the actual corruption - how Bernie Sanders and millions of his supporters were screwed by Clinton and the DNC.
I don't think it's partisan to expose the truth. To do otherwise serves those in power at the expense of the general public.