I think it's a good thing that the last SW I had watched was Episode III; this was my first teaser of the Disney era, and what can I say: I will not watch this one, just as I did not watched the others.
(For me, the Star Wars franchise is Star Wars from 1977, and I don't care about the other films or television series.)
They wouldnt have had to die in anh. They could have been demoted or moved to other positions. Or could have been technically vadered. It's not like lotr where we KNOW they don't exist. It is merely highly unlikely.
But I also dont remember many, if any, prominent female imperial officiers pre dibsney