That title is rather clickbaity for a "science" magazine. Crucially, the tree prominently featured in the large picture is not 10,000 years old and only its root system originates from that period: > Today Old Tjikko’s tree trunk is only five metres high. Although the spruce may have had many such trunks over the millennia, the tree's root system has survived all these years. No part of today’s living tree is as old…
What is a "tree"? None of the leaves on Methuselah are 5000 years old, but we say that the tree is that old. Kind of a Tree of Theseus situation going on.
It says that its trunk is about 5,000 y.o. as counted through growth rings. I would think most people would understand this to be the proper age of a "tree".