One can tell by the numbers of apartment buildings being built
There is a massive amount of new apartment construction in Farmers Branch and Irving/Las Colinas. Valley Ranch is pretty much built out, as is Coppell, judging by the McMansions going up on the few lots remaining.
The area of Las Colinas, specifically Lake Carolyn, is designed for millenials: condos, and an entertainment district that includes the Toyota Music Factory. DART light rail is accessible for those who work in downtown Dallas. It's a very nice area, with upscale homes north of Las Colinas.