This is a great point - communication is a vast array of information channels. “Motion” is communication whether or not it evolved to be, and so is every other aspect of occupying space in a biome.
And given that the organism under scrutiny is fungi - which contains many sprouting heads of the same underlying organism - one would have to have to have no familiarity with life at all to be surprised by intra-organism communication.
Would an alien encountering human language say "whatever it is not fundamentally different from the fact they shed skin cells in each other's space"?
> The research, published in Royal Society Open Science, found that these spikes often clustered into trains of activity, resembling vocabularies of up to 50 words, and that the distribution of these “fungal word lengths” closely matched those of human languages.
I'll be the one to admit I am surprised by this (if true), even with the understanding that any motion or byproduct whatsoever might be communicative.
The thought that an organism is totally isolated from its environment, itself and other organisms is absurd, sure - but no one said that!
And given that the organism under scrutiny is fungi - which contains many sprouting heads of the same underlying organism - one would have to have to have no familiarity with life at all to be surprised by intra-organism communication.