You can simply do a test and compare how much of a nutrient each age group has stored.
With age, iron stores increase, and vitamin A stores increase.
No one is arguing that iron levels do not tend to increase over time in healthy individuals, but at some point most people's ability to absorb, nutrients, vitamins and minerals begins to decrease. So we have examples such as rlmorel who had an issue with excessive iron in his system who reached an age where this was no longer an issue.
In most parts of the world iron deficiency is more of a problem than excess iron in people's diets. In our country red meat is available to the point that people eat more than what is required in a balanced diet. With the high protein lunacy that has been the rage for years now, red meat is actually the foundation of many people's diets. Is it a good idea for older folks? Very doubtful. So I think that I understand where you are going with your line of reasoning, and we probably would be allies in most discussions.
I still question the legitimacy of the study that the thread is based on.