Biblical Names and Poetic Etymology

With place names, there are changes. You get this sort of retroactive field. For instance, in Genesis 1921, a place where a lot in this family, flee, is referred to as mitzar which means smaller and significant. The name of the place gets referred to from here on after Addison Zohar. So again, you can have these sorts of changes, but how would we know it's retroactive? Unless we're told in the text, well, this was the name at one point and here's, this is the name now going forward.