Full release notes: https://wiki.arcengames.com/index.php?title=AI_War_2:Post_Completion_Part_II#5.615_Sidekick_Mod_Updates
For the most part, this is just some balance and bugfixes so the Dark Zenith Empire, plus in general a fix to the Scourge Bane. All of these are part of the excellent Sidekicks mod, aka the 4th unofficial (free) DLC for the game, by Badger.
In unrelated news, getting closer and closer to Heart of the Machine! https://store.steampowered.com/app/2001070/Heart_of_the_Machine/
It has seen a number of updates to the demo for everything from localization to bugfixes and balance lately, too.