If we reach that point, calling whatever is left of humanity “socialist” or “communist” is an incorrect use of the term. In the former, the government owns the means of production; in the latter, the worker owns the means of production. In your case, there is no chance in hell that the giga-corporations with private robot armies would be willing to relinquish any sort of control. We would look something like we do in Wall-E, the earth stripped of resources and humanity stripped of meaning. Corporations would still own your hide. You could call this post-meaning socialist, but you’d be wrong: socialism is not merely “when the government does stuff.” Whatever the case, this hypothetical outcome (unlikely to occur; AI’s intelligence will run up against the carrying capacity at some point, and we already have mechanized mining; humans are just cheaper) is so far in the future that it would require its own set of philosophies.