I don’t see it as a matter of keeping information from the public. The wording on the sign would be technically true, but the clear implication would be that the area is particularly dangerous. Why else would there be a sign? If the area is not particularly dangerous (which is what experts have determined) then the sign is actually causing the public to believe something false.
It’s like those California warnings about cancer-causing chemicals in pretty much everything. They’re not literally false but they don’t take relative risk into account and the right thing to do is to ignore all of them. To the extent that the public doesn’t ignore them, the public has been misinformed by the California government.