Blizzard have released full patch notes for the upcoming PTS update that is scheduled for release tomorrow - 21 November 2018. The patch will give an early peek at class set balancing, seasonal buffs and quality of life improvements.
Blizzard is launching the PTS Patch for some "rapid-paced testing" before the update officially comes to Diablo 3. They have included some long-requested changes in the new patch such as quality of life changes, class armour set balancing, a new game-changing seasonal buff along with many other improvements.
The testing will last for one week, starting on Wednesday, 21 November 2018 as Blizzard asks players to help them with the implementation by focusing on changes that affect their class in particular. The developer encouraged the players to break things as much as possible in order to have a smooth 2.6.4 launch.
Quality of Life changes in the new patch will include five additional armoury tabs for all characters which will bring the total number to 10. A new red beam marker and minimap pentagram icon for Primal Legendaries drops have been added along with new background and red border on icons.
Some Greater Rift changes have also been made. Players can no longer swap Paragon Points while the Greater Rift is open, and the option for public game matching is now added when the Greater Rift is open. These changes to matchmaking have been implemented to help the players find Greater Rift groups much easier as the previous matchmaking window was typically very small.
During the Season of Grandeur, seasonal buff will give all players a legendary power from Ring of Royal Grandeur but this buff will not stack if the players have additional Ring of Royal Grandeur equipped and unlike previous seasonal buffs, this one will not apply to Non-seasonal players.
Many armour sets have been tuned to improve class and set diversity at higher level Greater Rifts. The changes have been made to set bonuses which have been increased significantly but Blizzard have mentioned that these values are not final as they anticipate some adjustments to occur during the testing.
You can check the full patch notes on Diablo 3 blog.