I had a similar reaction when Tesla first announced they were developing Autopilot -- I didn't think they had any expertise in that area, other companies had a huge head start and developing compelling electric cars was already a huge challenge.
But they very quickly developed the best system on the market and I realized that I was wrong -- Tesla's thinking was way ahead of mine.
Tesla has been working on its AI chip for a while now and is sending signals that this will be an important area in the future for them -- in fact Elon has said that he thinks their AI hardware will be the best in the world.
Elon Musk says Tesla is working on custom AI chips
Speculative but it wouldn't surprise me to learn that Tesla's AI hardware is far along in development by now. I am keeping an open mind but am excited to see what Tesla comes up with.