There's still the issue of them doing the math to figure out the appropriate royalties. And if it turns out that the artists/other creators were never originally compensated for their work being borrowed, then DC could be in a lot of shit.
At Fan Expo this summer, I went to the DC Sunday Conversation panel, and Dan Didio asked the audience to talk about the craziest/weirdest/funniest comics they'd read. I put up my hand and described and quoted the "forty cakes" entry, but I prefaced that with "I'm not sure if you've ever heard of the Super Dictionary..." and explained what it was. Didio seemed to have a vague idea of what it was, and he kind of muttered something to the effect of "I'm not sure if I'm supposed to know about that."