The post mentions TiberianDawn.dll and RedAlert.dll, I assume it's not the whole source of the games, is it?
Here’s the language they use: “Electronic Arts will be releasing the TiberianDawn.dll and RedAlert.dll and their corresponding source code under the GPL version 3.0 license” I assume “their corresponding source code” means “the code for those DLLs”, but I do wonder why they bother mentioning the DLLs at all.
So the talk about open source might just be marketing fluff.