Yeah it will interesting to see how they handle the mindflayers and the Gith. I'll be watching to see if they overly humanize the flayers. Flayers are alien, they are only evil in the sense that we are cattle to them. They're like hyper intelligent version of the alien from Alien the movie -- we are a source food and breeding pods and we are otherwise beneath their contempt. They no more want to negotiate with us than we would want to work out some sort of deal with a flock of sheep.
Hoping not -- that's the mistake that Star Trek made with the Borg -- the Borg were the frightening because they couldn't be reasoned with. "You will assimilated, resistance is futile" end of conversation. Yikes, an enemy unlike any other in the Star Trek universe. At least you could make a deal with a Romulan . . . And they give the Borg a queen and then and then . . .
The flayers are frightening because they violate the normal rules. Equipment / abilities that defend oneself against psychic attacks are incredibly rare . . .
The Githyanki are developed something like the society that could have emerged if Spartacus was successful -- what the slaves took over Rome, made some Romans slaves and declared an endless war of genocide on all Romans? The Gith should be ruthless, seething with resentment, and quick to explain how all their terrible actions are justified in light of all the evils infliction upon them by the mind flayers.