Patch 10.0.5 adds an achievement for Lunar Festival 2023 which is currently slated for January 20, 2023.
Elders of the Dragon Isles is a new achievement added in Patch 10.0.5 Build 47118. It’s tied to Lunar Festival and Honoring the Elders. Either Blizzard will hotfix the achievement to the live version of the game or Patch 10.0.5 could potentially release before January 20, 2023, when the event starts.
That said, the first 10.0.5 build is dataminable, but not available for testing just yet. With the Holidays approaching, the test phase would run for less than 30 days if the update were to go live on January 20.
10.0.5 seems to be relatively minor and focuses on the Trading Post and small quality-of-life improvements to the game.