Doesn't matter. Copyright, without the licensing exceptions, won't allow EvilCorp Inc. use your code even if you publish it in the clear on the internet.
Also, more relevant to the discussion I was responding to, the GPL license doesn't allow re-licensing without consent (or a pre-arranged copyright assignment - a contributor's agreement). And it's copyright law which enforces this.
DCOs don't give copyright ownership to anyone else or even any more rights to anyone else. It is simply a declaration that you have the permission to license the code you wrote under the license you're giving it for.
Also, more relevant to the discussion I was responding to, the GPL license doesn't allow re-licensing without consent (or a pre-arranged copyright assignment - a contributor's agreement). And it's copyright law which enforces this.