The contract would pertain to any work ever made by the contracte. You said you wanted to abolish copyright, and that mean you can't pick and choose to keep copyright around when its suitable. It would also work indiscriminate, cover any past or future work in software, pictures, music and so on.
If you never intend to sue over IP, then the contract should be an no-issue. All it does is to write down that specific aspect into an enforceable contract. Contract don't need to use men with guns if everyone choose to honor it, which was the historically method used back when people lived in tribes and villages made out of a handful houses. No one would dare to break their word, risking that others would start to do the same.
