> Literally the only important thing in life, the basis of all value, the formation of self-identity, comes from communication with other human beings.

I think you're mistaking their sarcasm for sincerity... especially considering the emphasis on self-identity ironically juxtaposed as originating from a decidedly non-self activity, which has all the hallmarks of being intentional...

On the other hand, reading their other content leads one to believe that they may, in fact, be serious... hmm...

It is unironically correct. Well, interaction with other human beings may not be the only important thing, but it is certainly far and away the most important thing.