He loves a kid he Just met more than his own children, as per shown in manga facts:
Those are true love feelings and emotions right there. It is such an emotional panel.
This is something Naruto has never demonstrated for Bort or Himiwiri in canon.
Looks like Kawaki just happens to be the main one, but there are many other kids like him out there:
Guess now we may have the answer of who Sarada, Mitsuki, Sasuke & co. will be fighting in the timeskip.