As I just posted in a thread in GQ, I would personally appreciate it if people would stop doing this. The “joke” is beyond old. And when you just post a zombie joke, or worse, “Braaaaiiiiins,” it serves no purpose. It doesn’t inform the newbie of the policy, or why it is frowned upon. It’s almost as annoying as spam. If you see an old thread bumped, just report it. There is absolutely no reason to post a zombie joke.
This said, I don’t think there is any reason to make a new rule on it. Lame jokes by themselves aren’t against the rules, and I don’t think there is a reason to prohibit them.