It's not new or surprising that there are cave drawings and petroglyphs that are much older than the oldest writing, nor that such art is symbolic in some sense. It would be surprising if this art was writing, but this article gives no indication of that.
The nearest thing seems to be the claim that "the signs and the animals were meant to convey ideas just as a written language does", which is linked to an article by Miyagawa et al. ( https://www.frontiersin.org/journals/psychology/articles/10.... ).
I looked at that article. To call it speculative might be an understatement (although the authors are clear that what they are doing is speculating). It includes reasoning like this:
> Waller (2002) points out that the pictures often cluster in areas with enhanced acoustic properties. For instance, in the deep caves of Font-de-Gaume and Lascaux, pictures of hoofed animals such as bulls, bison, and deer appear in chambers in which the echoes, resonances, and reverberation created percussive sounds that resemble hoof beats7, as illustrated in Figure 2. In contrast to this, in chambers that are acoustically quiet, one finds pictures of felines (Waller, 1993a) or simple dots and handprints (Hoffman, 2014).
> Cave art, as analyzed by archeoacoustics, shows a flow of information from one modality to another: auditory to visual. The auditory modality is triggered by external input—thunder, rock tapping, music— and the auditory representation is mentally transformed into external, visual representation. This is a pure form of externalized symbolic thinking where information from one modality is transformed into representation in another modality. We speculate that this activity of information transfer across modalities allowed early humans to enhance their ability to convey symbolic thinking to their conspecifics, as well as their ability to process acoustic and visual input as symbolic (i.e., to associate acoustic and visual stimuli to a given mental representation).
So. . . because cave paintings are found in places where sounds resonate, they helped us communicate symbolically. Uh-huh.
Later they list "striking similarities" between cave art and human language, including as separate points that they "are used for communication", that they "express actions, states, objects, and modification", and that they "externalize internal mental states". Ah yes, as opposed to all those other communication mechanisms which somehow communicate without externalizing internal mental states, and without expressing actions, objects, etc.
The article also heavily cites Chomsky at his most nonsensical (e.g., https://www.sciencedirect.com/science/article/abs/pii/S01497... ), where he speculates wildly about the evolution of language while clinging to tenets which are at best implausible from an evolutionary perspective (e.g., "the optimal conclusion about the nature of language would be that its basic principles are extremely simple"). And that's to say nothing of his upside-down view of language in which communication is regarded as secondary to its function as a "system of thought".
Again, to be fair, the Miyagawa article is up-front about being speculative. But even so, its speculation seems rather extreme and I don't see any actual data supporting the hypothesis that cave art is writing rather than just some form of symbolic representation.