Ahead of the Major Qualifiers this autumn, a new balancing patch it due to tweak Dota 2's meta.
Rather than making some of the bigger changes that are in the pipeline, the scope of the 6.85 patch has been limited so it doesn't affect the Majors.
This news comes from a forum post from a Dota 2 admin called IceFrog, who hints at bigger changes to come after the Majors, in the 6.86 patch.
The patch follows the massive changes that came with the game's huge Reborn update, so I can see why they'd be concerned about adding more major changes so close to a tournament.
But with the reduced latency of the Reborn update and the balance tweaks of 6.85, we should be in for an interesting, and hopefully problem-free Majors.