Sure but what I am struggling to understand here is that these sets of communication elements must have been generated in the first place by the animals that use them, so this resolves nothing really. Is there something I am missing here?

Hmm, purism can take many shapes, it’s not a strictly formulated stance (even though it might act like it is “scientific” because it minds etymology). It doesn’t have to be negative towards neologisms, in fact it can be very positive towards them if they’re based on native material and are meant to replace loanwords.