basically that she stopped getting updates in patches from what I gathered from the datamining threads/vids etc. We know her story role got filled by a certain archdruid, and now we are getting Jaheria in the 'druid slot'. I suppose a halfling companion could still be possible, but I think it would be pretty different than what original indicators pointed towards.

Hell, Minthara has gotten stronger indicators these last couple of patches as a possible companion. It just seems likely that Helia ended up on the cutting-room floor like the other origins/companions that were indicated in the very first datamines.