Yes it’s true.
The well of eternity blew up ten thousand years before WC3, with said exploding the high Bourne that stood against the legion had a culture shift and stayed in the same area all of that time growing and developing there new culture with only a handful of times they left the areas to deal with threats.
The race predates the sundering by like 2000 but even then they lived in the same area and post sundering they never left it.