To me this whole situation seems to be a pretty good example of what not to do if faced with a copyright claim. It's tempting to see outfits like The Onion or Cards Against Humanity doing this kind of thing and feel like you are bulletproof and can do it too. But it's pretty easy to tell when these 'open letter' responses have not received legal review.

Waffle House had a legitimate claim and acted on their obligation to their trademark.

There is a pretty good argument that Waffle House continues to have a claim.

They probably wont do anything because its, frankly, a waste of time.

This could probably have been avoided entirely if copyrights were correctly respected from the beginning.