The Thrall/Garrosh thing is actuall a good point, that they didn't interact at all was kind of a missed opportunity and the little last defiance for blowing up the boss was extremely pointless (though I'm glad we are finally rid of the roid-rage orc). Thrall and Jaina were in the raid though, and as others have said definitely had dialogue, to save Anduin. Her sisters never entered the Shadowlands and doing so for Veresa would be completely idiotic. She has a family, there is no reason for her to go prancing around the dead and looking for her own death. Valeria on the other hand would have made a bit more sense, but she wasn't part of the initial crew and I'm sure her unstable voidy underlings still need all the help they can get, even if Varoc doesn't want to admit it.