Yep thats exactly the point, a good number of gun owners want the shortest length semi AR style rifle thats non restricted as possible. The closer companies get to that the more money they make.
I believe a barrel like this could be made as faxon already does it, theyd just need to add 2.6 inches (let me clarify, not add another piece of material, i mean figuratively add, ie machine one piece that is 18.6 inches rather than the 16 inch version they offer now.), which theyve shown willingness to do on a few canadian specific barrels (have one currently on my modern sporter). I got my faxon barrel in the $300s, i cant imagine the brake version they already produce would be much more in an 18.6 variant, and whoever brought them in or made them (TNA being my preferred company as they listen to their customers and respond with feedback regularly) would sell out fast.
Just my 2 cents and its just for their consideration, alot of people here have responded positively and i think alot more will (if they can get past the unrelated shotgun and m1 carbine debates lol)