Why Scandium and Yttrium are not-strategic metals (according to Wikipedia)?

This is a trick question. They listed heavy metals with a density of more than 5 g /cm3.
Scandium and yttrium are light metals, so they are not listed. Scandium has a density of 3 g/cm3 and yttrium 4.5 g/cm3.

https://en.wikipedia.org/wiki/Heavy_metals

You will receive answers to your questions here: "The consulting on concentration of minerals"