Not a lawyer. I suspect it's not enforceable as a contract, but that it is a valid revocation of the license. That is to say you could still use the project wi

Not a lawyer. I suspect it's not enforceable as a contract, but that it is a valid revocation of the license. That is to say you could still use the project within the bounds of what you can do without a license, but not do anything that copyright law restricts (e.g. reproduce the copyrighted material).