Cameron Waldrop
Before we go any further, there is also a summary video to accompany this new patch. You can see it below. While there are tons of changes, there is also a section of highlights that are:

Regiments of Renown II introduces a whole new set of elite troops to all seven factions—this time with a focus on mounted units!Land Battles have joined the ranked matchmaking queue!Miao Ying can now (properly) use her Eye of the Storm ability in combatAdditional character trait reworks and skill tree updates for the Legendary LordsSeveral adjustments to make the Realm of Chaos less punishing or tediousMuch-needed adjustments to how the AI Tzeentch faction utilizes Changing of the WaysImprovements to the Cathayan Formation Attack abilityFixes to the Kurgan Warband spawn rates during the Grand Cathay campaignNumerous improvements to unit responsiveness to orders and movement commands in battleAI improvements to their battle strategy, as well as fixes to prevent them from abusing skills and abilitiesVarious fixes for player-reported issues and feedback notes

You can find the comprehensive list of changes over here.

Total War: Warhammer 3 Blood for the Blood God III DLC Is as Bloody as You Expect in New Trailer Total War: Warhammer 3 Trailer Shows the Massive Immortal Empires Map & its Legendary Lords Total War: Warhammer 3 Champions of Chaos DLC Gameplay Lets You Witness Valkia’s Bloodlust Total War: Warhammer 3 Reveals Demon Princess of Khorne Valkia the Bloody as New DLC Legendary Lord Total War: Warhammer 3 Teases Female Champion of Khorne for Champions of Chaos DLC
Total War  Warhammer 3 Update 1 3 Brings AI Improvements   More - 9