I can't think of any times when people have had their lifespans shortened for fear they would become the elite, and the shorteners were on the right side of history. That sounds more like The Crucible.

The point is they are not potential elite, they are already elite. The fact that they can get hold of the treatment when the majority can not shows they're already placed at the top of society.

Personally I agree with the logic that if we have the choice between 0 and 100,000 people living for ever we pick 100,000 (Even if that 100,000 include such greats as Un and Assad). Having said that If I had the choice between 100,000 living forever and 3 billion people living forever with less private jets in the world I'd pick the later. Perhaps I'm cynical but if we do indeed get this tech I'm a lot less confident about my values being satisfied in the second instance than the first.

French Revolution versus Red October, Mao's Cultural Revolution, gulags and concentration camps for every communist country. In 90% of these "elite trimmings" society is pushed back decades at least. Unruly mobs do not move the world forward.

They may not move their country forward, that doesn't mean they don't move the world forward. Say what you will about the French revolution's effect on France but it greatly influenced the spread of democracies and republics world wise. Similarly the presence of socialism(in the production owned by the people sense) hugely encouraged improvements in working conditions in countries that feared similar upheaval and loss of property.

But I wouldn't argue with you that the majority of these 'elite trimmings' set the society back. The question is after the set back does it move forward faster than it was or in a better direction (Often the answer to this would be hugely reliant on your personal values).