In usa everything that is copyrightable, becomes copyrighted at moment it is created. For instance that sentence, and this on, are protected works owned by me. The only reAson HN can legally use then is cause I gave them license, buried somewhere in Eula/site terms of use.
Also, an architecture is not copyrightable. Maybe patentable. Copyrights protect specific expressions, not a general idea, plan, or architecture. At least not yet thankfully I haven't seen anyone try to argue an unrelated software doing same thing is a derivative work.