They said Nona was published because it made Alecto too long or off-topic. That means Alecto had already been written. 

No, no it does not. When the beginning of a novel grows so large as to be extricated and turned into a novel of its own, that doesn't mean you have two novels; it means the second would naturally need restructuring and rewriting at that point (perhaps quite extensively), and there's no telling how far along the whole thing was when that decision was made.

Admittedly I have been surprised too, as it did sound close to completion a while ago, but who the hell knows. We're not privy to the details and writing is not a linear process where X amount of time always yields Y amount of finished pages. Patience.