Since there's only one question tagged code-generation, I'm tempted to just retag it. Is that the appropriate action? It seems strange to me that if somebody makes up a tag, others must get reputation in it to point out that it's redundant.
Since there's only one question using the code-generation tag, and since it clearly falls under metagolf, you should just retag it. There's not much point in creating a tag synonym for a single-question tag, at least unless you anticipate the tag getting more use in the future.
That said, dmckee does make a good point that code-generation could potentially apply to non-golf challenges too. I don't think we need both, but I could support renaming metagolf to code-generation instead to make it more generic. (That could also be done manually — it's only four questions plus the tag wiki.)
I recently noticed the code-generation tag, which is a redundant with metagolf.
I'd say that this statement constitutes a claim that there no possible way to write a code generation challenge where the goal something other than golfing the generated code, does it not?
Give me a couple of days. I'll think about it.