In AI research, the acronym XAI stands for eXplainable AI [1]. To understand anything about the universe, AI will need to (i) make accurate predictions about some parts of the universe and (ii) explain the laws and the models it used to make these predictions, just like natural sciences do [2]. I believe eXplainable AI can get us there one day. However, I'm surprised that, despite it's name, xAI doesn't mention eXplainable AI and the team doesn't seem to have experience in eXplainable AI, which makes me think it's just another deep-learning AI venture.
[1] https://en.wikipedia.org/wiki/Explainable_artificial_intelli...