I am not sure why this is news to you, but yes, there is a variation in people's arms length vs. their height.
Have you heard of the term "ape index"?
It is pretty common for people's arm span to be the same as their height (Ape index=0). If the armspan is longer than height, the person is said to have a positive ape index. And some people have shorter arms (negative ape index)
Many climbers have positive ape index-- by 1- or two inches, but sometimes the difference is as much as 4 extra inches of armspan, compared to height. Positive ape index is generally seen as an advantage to climbers.
I have a friend whose ape index is about -3. She is taller than me by couple inches, but I have a slightly positive ape index, so our armspan is about equal. There are many situations where it does make a visible difference to how we climb. Even though our armspan is about the same, we often have to come up with completely different beta for the same climb.