Has anyone here heard of Keirsy/Bate's book "Please Understand Me?" I am quite familiar with the type INFX, being one, and these Indigo traits match up well with INFP/INFJ (INFX) personalities. If more people are now being born wth such personalities when once they were rare (INFP/J are the rarest of the types) then there must be a purpose for this.
Not to sound utterly weird but if they can see and hear angels then maybe that seems to be the purpose for their sudden number. Perhaps they are going to be "translators" between spirit and human as the "last days" end. (if you believe in the Bible's description of what seems to be these days) I dunno, just a thought.