Different languages arise in each simulation. However, it's not very human-like. But like a true language, the networks can understand some novel meanings. Batali's simulations suggest that evolution and learning play two distinct and vital roles. The similarities to human language stem from how learning and evolution interact.
Evolution dominates early and establishes the broad outline from which languages arise.
The view of language as an adaptive solution to conveying complex meanings with linear sequences has existed at least since the turn of the century in the work of Ferdinand de Saussure, one of the founders of modern linguistics. Not everyone agrees with it, but Batali's simulations seem to lend it some support. Nevertheless, fully understanding how language evolved remains a long way off. I know much more about how language couldn't have evolved than about how it did.