> For a while, we thought it was language and then discovered that it wasn't.

When did this happen? I only studied linguistics at the undergrad level, but as of about 5 years ago, animal language has not made it there other than some examples of 'here are some non-human communication systems, and this is of they differ from language'.

It is not plausible to say that linguists are simply too egotistical to consider the possibility. Scientists in general love animal models. Plenty of linguists would jump at the chance to conduct experiments that are way too unethical to do with human subjects.

There is some promising research into whale songs which might turn out to be analgous. However, as far as I have been able to find, our understanding there is still largely speculative.