Hello, Habib! (I hope that you don't have your prefs set to wake you up when I leave a message on this page.) The New Discussion tool might be released as a Beta Feature this week. Maybe. I hope.
Whenever it happens, here at arwiki, it will be a "recycled" Beta Feature. If you turned on (and kept on) the Reply tool Beta Feature, then you should (they hope) get the New Discussion tool automatically. For most editors, the Beta Feature will be off, and if they want to try it, they will need to go to Special:Preferences to enable it.
I'll let you know when I find out what the schedule is. Thanks,