I think this is intentional as, like the aforementioned Kane Superman HC, they are only including the books done by that creator.  I think GLC 1-5 is supposed to be Green Lantern Corps: Recharge 1-5, which Johns co-wrote.  While I'm not thrilled about the lack of GLC either, I think it still works nicely as a collected format.  Either way, I'm picking it up.  Huge fan of that run.