I agree with you.I think,that Sylvanas is such overused character,that has served purpose long ago.Yet,they don't want to put her down because of her fanbase.Heck, I guess I'm the only one,who finds her BfA trailers "FOR THE HORDE" more like a mockery of it.By shouting it,she doesn't mean it,she just attempts to rally her forces who are biting the dust one by one.You can see how she actually treats the Horde not only from post-Legion cinematic,where she doesn't even finds necessary to raise her cup and join the whole "FOR THE HORDE" cheer,you see her attitude towards the other members of the Horde but her precious forsaken in the fragments of the latest novel.She doesn't care about the Horde,she doesn't care about the honor,she doesn't care about her own allied races...All that she cares about,is her personal interests.Having such warchief is disgrace to the Horde and kills any wish to play on it's side.