Yeah i never really expected to get sets of 5 for the WE everytime from now on, just because we got it that one time doesnt mean its a given from now on. But i dont think that multiple tamarins for example are completely impossible since the butterflies actually do have more differences than their 2d wing textures, namely the bodies are different in each species. But tamarins would require more work than that for sure.I rather have one useable and functional monkey then one stuck in a way to large boy that wont have more then species anyways.
Just look at the sloth, if frontier would give us multiple exhibit tamarins they also would have given us both sloths to make everyone happy, but they didnt because butterfly wings are literally just 2D textures while a new sloth or literally any other animal needs a new Modell.
So sorry to break that illusion but if it isnt a literal reskin which tamarins cant be by the simple fact that they all have different morphological features that are instantly apparent with the lions mane, the emperors moustache and the cotton tops fuzzy hair, making them possibly the worst options for reskins as you cant have a maneless lion tamarin or a cotton top with a mane
I could easily see scarlet and blue/golden macaws coming as a set one day since they are litteraly a color swap besides from minor tweaks