We're not Adobe in this forum, we are just Lightroom users, not Adobe employees.
You'd have to ask Adobe why they haven't implemented this.
do any one knows when Adobe going to implement this?
They probably won't if they haven't already. LR CC/6 has been out for a few months and they still haven't carried over the plugin to import images from the new Photos app.
But I must ask. If you are using LR why on earth would you still be using either iPhoto or Photos. That is just Totally counter productive.
Pick one image manager and editing app and stick with it, good or bad.