The him dying on stream thing is just a joke saying that, due to his poor spending/life decisions, Phil will never be able to retire and do anything more meaningful with his life. It's also a statement on how sad his social life is, because, if he wasn't streaming, what would he really do? I think even Phil has a limit on how much Champions he can play each day, especially without a steady stream of tips to support his pulls.
Even with his poor health, the actual odds of him having any sort of medical incident on stream, let alone dying, is incredibly low. There's tons of unhealthy cows that have streamed for years without issue. And I don't just mean the lolcow variety, but actual cows who live the hermit lifestyle because they're too big to leave their home as opposed to being paranoid.
Phil isn't exactly the most loyal streamer in the world. He's dropped streams before because his ear hurt and he complains about the equivalent of a papercut. I think if he was experiencing anything serious, he'd use it as an excuse not to stream. There's arguably an over/under on whether he's too much of a hermit to go to the hospital. IIRC, hasn't he treated the ER as a doctor's visit when he was dealing with ear stuff? If he's willing to leave the house over something that minor, I think he'd leave (or more likely call an ambulance) if he was having a severe issue.
