I appreciate this discussion is already kind of resolved over at Questions about Drupal 8, and possibly at Questions about contrib/core developement (although there wasn't much discussion there) but this question is slightly more specific.
There was a question tackled by MPD and Letharion (Creating Drupal 8 route for AJAX requests) asking for help in creating a Drupal 8 core patch. Surely these kind of questions/discussions should be in the relevant issues in the issue queue for D8 core?
Long story short, should we be helping Drupal 8 core development here?