I agree with the position. I'm not going to ask a child who has mainly known the US as home, to leave. This is in-line with my general thoughts on the innocence of children and the spirit of being a nation of opportunity and dreaming of something more if you're willing to work.
I also agree it would seem to be a big mistake to do this prior to pushing through a wall or other enforcing mechanism. Conversely, are ICE arrests and deportations up? It's possible the wall is now only symbolic and enforcing existing laws are the "wall" in actuality.
The downside to calling proper enforcement the new "wall" is the next Dem president can simply choose not to enforce law. To that end, it would seem wise to put some infrastructure in place for the areas of the most egregious illegal activity. For a bunch of the border, a drone operated detection system backed by proper enforcement would seem appropriate.