i watched mystery inc back in the day but hadnt played higurashi (and im still not very far in it) so i was skeptical when i heard about the reference, but apparently its 100% real. i definitely remember the cicada episode if not the finer details.

its also very funny that an entire scooby doo episode would reference a 5 year old visual novel in 2010, when even more recent shows like steven universe don't get much more obscure with their references than utena, akira or dragon ball.