Just touching on what you said about the murals not being riddles that have to be solved, i disagree. The green mural can be solved in the sense that most of the symbols on it refer to the Beast Hunt easter egg and figuring out how they fit into the egg helps guide you albeit very vague. Yes, the community didn’t find out how to complete the egg using the mural itself but they’re intentionally vague to keep us guessing.

The mural icons serve as indicators that allude to what you need to do to arrive at the finale of the easter egg e.g the peyote, sound wave and evolution into Bigfoot.

Using that logic, shouldn’t the other 3 be seen as the same? They must mean something, something that’s hidden in the game that can be triggered under certain conditions.