I have no problem with the idea of people who have survived some bad experience being referred to as "survivors" of it. But the generic use of the word "survivor" as an all-purpose replacement for "victim" has always bothered me. The more I think about it, the more I detest it.
Because, what about the victims that DIDN'T survive? If, for example, you say your organization "advocates for the survivors of ___", you are explicitly excluding those that don't survive.
"Survivor" can be a pretty broad category, including those who brush off a bad experience and those who are traumatized by it but make it through anyway. But it doesn't include those who are outright killed by the bad experience, or those who initially make it through but then die for some other reason such as suicide or accidental overdose because they can't cope with the pain or memories of what they've been through or how the experience changed them. It might eve make those who aren't sure yet if they are going to make it through feel excluded.
So, if you're intending to refer to all victims of ___, saying "survivors of ___" is not appropriate. So what do you call those who didn't survive? Are they victims now? But if you abandoned the word "victim" in favor of "survivor" because you thought "victim" was demeaning, it's kind of rude to apply it only to those who didn't survive. They weren't necessarily any weaker or more passive than those who survived. There are a lot of factors outside a victim's control that determine survival.
You could say "survivors and casualties of ___" if you want to be inclusive. But it's simpler to just say "victims of ___" and define it simply as "people who have experienced ___" and not apply negative associations to the concept of "victim".