Comey could’ve simply released a statement that the new info is not serious enough to reopen the investigation, which would’ve had the same effect as clearing her. Reopening the investigation does nothing positive for Hillary.
Then why say ANYTHING at all? No, the point would be to create a couple of days of distraction and make this the news story, and let the Trump campaign waste valuable time touting it, and then have Comey declare it a non story, so the next couple of news days would be about how the stupid Trump campaign wasted time on this, and more importantly how it discredits any future releases as well (the worst of which may be to come in the next few days).
I'm not necessarily agreeing with the post (I hope this is legit and helps to sink her), but commenting on how the post may have merit and how this may be a ruse.