"communication" and "language" are two separate things, and the article title mistakenly refers to a certain type of communication as a language when it is not that. This was the main takeaway from the ape sign language experiments - apes can learn to associate signs with objects and actions, but they cannot form sentences, instead what is observed is that the ape brute forces whatever they're trying to communicate by doing the relevant signs in random order until the researcher gives them what they want (usually food or attention).

Still cool that things like pointing are so universal that they cross the species barrier though.