The concern isn't that these children will be raped or that pedophiles will rape them. It's much more subtle: these are children who are taught from a young age to be exploited. They are taught not to have boundaries with strangers, to tie self-worth and sense of self to external validation, and to squash down their own feelings of discomfort or even danger in order to placate authority figures around them. These are all things that they will have to spend a lot of resources and time unlearning to grow into healthy adulthood, hampered by the fact that videos of their exploitation will be continually on the internet for everyone to see for the rest of their lives.
I think this assumes that pedophiles are born with an attraction to children, as opposed to somehow having formed a mental association between children and sex through environmental factors. I wonder if there is evidence in either direction? From an evolutionary perspective the latter would be my default assumption, as the postulated evolutionary rationales for, say, homosexuality, at least, would not really apply to pedophilia.