That seems like an unfounded inference. Plenty of animals have more neurons than humans but lesser cognitive and language abilities. Language has lot to do with structure of the brain in addition to neuron count.
That doesn't mean language ability is a natural outcome of crossing a certain threshold of brain complexity; if anything it's more likely the other way around: this complexity being be driven by highly social behavior and communication.
1. https://en.wikipedia.org/wiki/List_of_animals_by_number_of_n...
Birds have areas of the brain that we would consider language alike. Both for native bird communication and I would also speculate that for human to bird communication.
If you have ever owned a parrot this is blatantly obvious since they actively communicate and vocalize both observations and needs/desires