They expect -- they've been told--- that they'll also get "permiso," but in this they are victims of an exploitative Hemispheric fraud which is lying to them and using them as a human battering ram.
Giving "permiso" is not a part of "welcome."
It should be "Welcome to processing. You have been cruelly deceived, but we honor your citizenship. Since all of you are legal citizens of El Salvador, Guatemala, and Nicaragua, you will be safely returned there as quick as we can get you ID'd and medically screened. The costs of this will be deducted from our foreign aid program. Have a pan dulce."
Then I guess the Pope's words were superfluous.