You can download PTS now to download a majority of the update - we are making a few changes right now that will be published later tonight, but shouldn't be a very large download.
Just hoping any outfit war stuff doesn't take people off the main server, leading to less organised play in the proper game world.
As mentioned during the stream, we are planning to schedule the Outfit War seasons to run every 4 weeks, where only the final match will pull players for a max of 2 hour - assuming the match doesn't finish from score sooner. Everything leading up to these final matches will be done through playing the main game.
We are starting with 48 v 48 v 48 and have room to scale up quite a bit.