Blizzard has posted the Patch Notes for Version 3.4.2 Wrath of the Lich King Classic, which includes the Phase 3 Update that just went live on Classic realms.
Wrath Classic Patch Notes
Version 3.4.2June 20, 2023
New Raid: Trial of the Crusader and Trial of the Grand Crusader
This content becomes available on Thursday, June 22 at 3:00 p.m. PDT.