Considering there's quite a bit of content that's in C4 which won't be in the new releases for a bit, I don't think it should be removed, as a matter of principle.
However, maybe an explicit, bolded note that C4 is the older version, and C2 is the newer upgraded version should be added.
Not that that will stop the posts (the two F95 invariants - people asking about stuff answered in the OP and in postings directly above them; and idiots incessantly complaining about games no one is forcing them to download for free), but it might slightly reduce the rate