Blizzard has decided to keep the information locked down until the new patch is removed from the public test realm and that is common to make sure that all of the bugs are worked out before it goes live for all players. If you want to learn more about the public test realm, you can read about it on the Blizzard website.
You can also sign up to be a member of the realm and it involves a few steps to follow. In the end, you will be able to take your character list over to the new realm to try things out when there is a new patch. Once the patch is done in the testing mode, it will be released for the Playstation 4, Windows PC and the Xbox One all at the same time.
If you are playing on a console version of the game, you will not have access to the seasonal changes in the game, however the seasonal weapons are still available to find within the game.