I don't really agree because I think it's more or less the same situation as Keaton, but rather than an old Superman it's a young Superman learning the ropes and trying to live up to legacy. It would explain why the hard push for Jon in the comics even though there's a black elseworlds Superman coming and his TV version has no powers and isn't really going off his story.
The plan could simply be "lets tackle the Superman concept from two angles: self contained elseworld, and legacy coming of age in the main continuity." Neither functions as the "real" one in the traditional sense.
And I'm still personally keeping an eye out for a Legion movie or something...