Which is what I'm talking about. While Skyfall was simultaneously showing Bond's personal history right up front, laying it out there and eliminating the possibility his name wasn't James Bond, they were just as explicitly holding up Silva as an example of a 00 who operated under a pseudonym the entire time, to the point where Bond had to press M as to the nature of Silva's actual name. Silly as it may be (and I'm not even in disagreement on that note) - the part about it preserving continuity is what I think makes it a real possibility, and also relevant. The continuity is obviously way more important to EON now than it's ever been. That's partially why I think codename theory is in play - it allows them to stick to that continuity while giving them the freedom to cast new actors who can bring their own takes to "James Bond" - which as has been pointed out already, is just as much brand name as it is character name by this point.
At the point where Bond is literally nothing more than a name, especially since he doesn't really symbolise anything these days - in the way Captain America is a symbol for his country and its values, for instance, or Spider-Man is the bullied kid standing up for what's right, or the Doctor (Doctor Who) represents pacifism, curiosity, wonder, etc - he's basically reduced to nothing. You're not watching Bond, but a totally unrelated character who just happens to have that name and be in an action movie.
That's why, if a non-white actor is going to come in, I'd much rather they just reboot, as conceptually dreadful as reboots are in general. At least then, a modicum of the character - not that there's been a great deal to him in the post-Dalton era at all, if we're honest - endures rather than just the name, which is ultimately meaningless (other than for continuing the franchise by hook or by crook). So codename theory could be implemented without destroying continuity, but would still be profoundly stupid both logically and in terms of its damage to the series' creative value.
(And people who pretend codename theory has any validity for the Connery-to-Brosnan movies would still be cretins)