[Update #2]: Creative Assembly has fully revealed Thorek Ironbrow and the Ogre Mercenaries which are coming as a part of the free DLC.
[Update]: Creative Assembly has revealed the full scope of the upcoming Beastmen vs Lizardmen DLC, and I was kind of right about the mercenaries!
Total War: Warhammer 2's penultimate DLC The Silence & The Fury will be arriving on July 14, 2021, bringing with it a whole host of goodies for both the Lizardmen and Beastmen. While the exact details haven't been announced just yet, you can expect to see Oxyotl as a Legendary Lord for the Lizardmen and Taurox for the Beastmen, a variety of new units and heroes, unique campaign mechanics for both faction, and if the recent Wood Elf DLC is any judge, a massive rework of the Beastmen faction as a whole.
The good news doesn't end there, however, as Creative Assembly has also just revealed that there will be a sizable free DLC accompanying The Silence & The Fury. Once again very few details are currently available, but what I can tell you is that the free DLC will bring with it a new Legendary Lord, a new unit, and most mysteriously of all, new reinforcements!
What exactly that last part even means, I'm afraid nobody outside of Creative Assembly currently knows. If you are willing to indulge a bit of speculation, however, I'd say that this is likely going to be a new twist on the good ol' Regiments of Renown. Perhaps these will be mercenaries like the fan-favorite Dogs of War that can be recruited by any faction and consist of a myriad of diverse and exciting units. It would certainly be an interesting way to help spice up campaigns!
Whether my pipe dream is actually going to become reality, well, that's something we'll find out soon enough as Creative Assembly will likely be doing a slow reveal over the next week or two. Once that happens I'll make sure to let you know, but for now I'll leave you with a brief trailer highlighting all of the free DLC released so far. Enjoy!