I understand people's concerns about the lion, but I really don't think there is anything to fix here. The style is the same with other large carnivores like bears and tigers. Yes, they are all somewhat stylistic, but at least the style is consistent. A change to the lion would warrant a change to the rest of the large carnivores.
The smaller cats on the other hand, like the clouded leopard and cheetah are more photo-realistic. That seems to be a different category on its own.
The lion is just a favorite of many, and this is why these changes keep getting suggested. I don't think people are looking at all the animals objectively while making these demands: "My favorite, so it has to be perfect". But then every animal in the game is a favorite of someone else. We can't use this logic when demanding changes.
A change in the model of an animal should only be asked for if there is anything wrong with it objectively, not stylistically. The only thing I can say that is wrong with the lion is the name "West African Lion". The current lion with its fluffy mane doesn't resemble the actual subspecies. Perhaps a change in the name and scientific name would fix that problem. Other than that I see no problem with it. The style is consistent with the rest of the large carnivores. Plus I don't think making a less solid looking mane is possible with the current fur system, as seen with other animals like the orangutan. I think there are other animals that need some love before the lion, animals with more serious issues with their models. People either don't care about those animals, or don't know how they look like.