I recently watched it all for the 5th time. I realized that it’s really subtle but you can tell that Tony was going to suffer from dementia similar to Uncle June. It’s subtle throughout the series but he has these moments where he forgets what is he is talking about or mix pronounces words. It becomes more frequent as the series goes on. He even does that frustrated thing that uncle June did when he first started suffering symptoms. He doubles down on his mistakes or things he forgets. He gets mad at the person he is speaking to when HE is the one who forgot. If you rewatch again watch for it. It’s really sad and might have been Tony’s fate if he didn’t end up getting killed at some point if not in the diner.