Edit These are fake. The Dramatis Personae of GS3 doesn't list Abbaddon. So since that one is disproved it's likely all of this is fake. Mods can feel free to lock this or delete it at your discretion.
I know these are rumor, but a guy on reddit is doing an ama and claims to know most of the new 40k fluff for the big revision/advancement. The Tau stuff is a doosey. All of it is, but the Tau ones are relevant to this forum. If this is not allowed then lock and delete or whatever mods. Still this paints a very exciting picture.
https://www.reddit.com/r/Warhammer40k/c ... nding_the/
"The Tau stuff I paid particular attention to (guess my faction) and I was really happy to see a Kroot mercenary leader being front and centre, leading a cadre of disillusioned Tau. This is big, the first mention of Tau themselves straying front the greater good!!! Despite being psychically null, they find themselves able to communicate with the Chaos forces and play all sides against each other. There is a shadowy figure involved that I think is a corrupt ethereal"
"My thoughts exactly. I'm thinking splinter faction, these guys are far more amoral on the surface, but on the flip side try and recruit guard survivors as mercs. I think the pure greater good tau will be confirmed as dabbling in sterilisation etc"
"Not quite, but there is a significant chunk of it dedicated to Tau expansionism, hoovering up in the wake of the Imperium losing its grip. The Kroot and the Vespid both get a mention (the Kroot quite significantly) which is nice!"
"In essence there is a Kroot mercenary outfit, including some disillusioned Tau, who play off all sides. I'm guessing there will be a new release at some point? Or GW have a surplus of plastic Kroot
The vespid get one mention, of an attack on an imperial guard supply company at rest. Its quite impressive stuff, they home in on pheromones released from the guard"