The patch also marks the beginning of the game's third season for competitive multiplayer, a slew of additions to item drops, an item trade-in feature and a few other superficial bits and bobs. There are a few more details at the source link, and to help pass the time until the June 20th release, you should probably check out the new trailer embedded below.

Update (June 20th): The update is live, you can check out the full change log here.