As of now there's nothing but doubt, including doubt that EBR will ever deliver an AX... The goofy mock-up, while goofy...was a pretty clever play on some of the absurdity in the liter plus class of ADV pretenders, unfortunately Buell got the brunt of joke. It is possible to build large, heavy, over-powered, and capable ADV machines...
Yamaha has been the sleeper of the class that's getting more attention from serious ADV riders now looking for something more robust, actually off-road competent, and reliable. Competing sport bikes and cruisers in ADV drag don't seem to even be able to manage a short bumpy trip to Star Bucks without a costly calamity, or serious logistics planning.
Yamaha initially disappointed critical ADV enthusiasts with the bike's substantial heft, limiting 19" front wheel, and suspension travel -- but closer examination and millions of hard miles revealed carefully measured and balanced compromises in Super Ténéré's design: incredibly low cg (even a relatively small rider can get it upright solo), amazing robustness and the ability to 'limp home' on just about broken anything, decent fuel economy, mountains of train like torque -- all with stable forgiving neutral handling on all surfaces that won't exhaust a rider that's truly taking the rough and scenic rout.
There's some good lessons here that Buell (or anyone) could benefit from in exploring ADV bike design.