Seriously?

There would have to be some proof that they were still alive. If you are lost at sea and there is no body to prove that you died then you are still declared dead after 7 years.

No everything that has ever lived will die

You have no direct evidence of my birth, so can it be a possibility that I never lived?

We know enough about biology and human physiology to assume that after a given amount of time everyone will die. That is the default, no amount of wishful thinking will change that without some very compelling evidence to the contrary.

Of course not. Extraordinary claims require extraordinary evidence.

It is possible "you" will never die. The reason is a variation on the Schrodenger's cat problem. You can't observe yourself to be dead. Thus if the multi-world interpretation of quantum uncertainty is correct, anytime there is a choice between the observer being dead or alive, the observer will only observe the "observer alive" world of the possible multi-world's.

For example, if you have an emergency operation in which the probability that you will survive is extremely small, say 10%, you will always only see and inhabit the universes in which the outcome is in your favor.

I know this wasn't your question but because I've been educated as a quantum physicist I can't help but think in these lines.

No, for example, it is extremely unlikely that Hitler survived his bunker episode.

of course not

No, the idea is contrary to reason. No one has beat death yet, if they were alive over one hundred years ago it is a good bet they are dead now and after 150 years you can be sure of it.

That is not enough to warrant possibility, especially if the belief that said person never lived is not warranted as well.

I'd doubt anyone could live past 130 years of age, after their purported death with no body found. Always wondered about Amelia Earhart and also DB Cooper.

Yes, of course. This is true of anything. If there is no evidence of a thing, then there is no proof of it.

I suggest you watch Bubba Ho-Tep: