I agree with your "why risk it" approach 100 %, but from the opposite direction. Why risk the extra step if it is not necessary? Thinking about contamination, especially. I mean, I am talking about "normal" beer strength here. I guess with this higher gravity wort, it really is debatable, I would not say "do not do it" in this particular case. When the gravity gets even higher, i´d probably also do it. I do this in my meads for this and other reasons.
I know that there are many articles that claim this 50% dying thing, but this mainly goes back to people writing what they read somewhere else and at the end you find no tests to really validate this claim. On the other hand, I read about tests that people did themselves (normal gravity worts around 1.05 OG), and they could not find this yeast homicide that these articles talk about.
I for myself, never could find any different yeast behaviour or endproduct between batches that were rehydrated and those at which the yeast was just thrown into the wort. I know about many other people who experienced the same.
Long storry short, strong worts, rehydrate if you want to, normal or low og worts, don´t risk the extra step.