At first, I thought that he might have a shot at getting into the game since Ryou was in Darkside of the Dimensions and that Konami would take note of that since it was popular. But instead, it really looks like they would rather just pretend that he doesn't exist.
Is it because for normal Bakura to exist, the game necessarily needs to introduce "Change of Heart" into the game, but I think they're trying to make it as a premiere card in a UR box instead? Also Change of Heart is like Monster Reborn, categorically. All "taking control of opponent's monsters" in DL has costs so far.
Don't lose hope! Remember back then, who expected they'll make Bonz as unlockable, even tho's he's a very minor character! As long as change of heart aren't in any of the boxes, there's still that "lingering" chance! :)