It's already confirmed in the game that it's going to start on January 23rd, 2024.

Confirmed & Possible Changes Prediction in Diablo 4 Season 3

 Confirmed:

-AoZ will be removed once the Season ends (might make it back into game later).

- Melted Heart of Selig PvM Nerfs.

- Perma Red Helltide (55m on / 5m off every hours).

- Gauntlet / Leaderboards.

- Rod confirmed that Nerfs coming to Ball Lightning Sorc & HotA Barb.

- Improvements for D4 Gold Trading for Console.

- More 925 Item Power source outside of Duriel.

Hopes:

- Fix Snapshots in particular Element, Accelerating Aspect swaps, multiple Key Passives on Sorc, etc.

- Hopefully a fix to lags/performance issues

- Maybe we could see some Powers like Metamorphosis be integrated into the game (similar to Varshan S1 Rings)

Diablo 4 Season 3 Abattoir of Zir Build Tier List - D4 S3 TOP 10 Builds