The enemy of these telomeres is age: damage occurs to them during cell division, hence the part of the DNA which watches after the DNA is no longer to fulfill its duty: and that is an open door to all types of cancer.
In other words, if nothing kills you at old age, cancer will do it.
tl;dr low iron causes less cell cycle activity. which means less errors including deregulation which is what cancer is.
its not that ground breaking.
but the iron contribution is. its actually a bit clickbait because they focus more on increasing iron in old people to prompt better recovery of everything else.