First Page Follies--100% Pure Set-Up, Right?

In Batman '66 #5, we learn that...

Wait a minute!! That's completely new information!! This was never mentioned on the show!!

Swept away? Never seen again?!??

You know what that means, don't you?

Uncle Walt will be turning up as a super-villain!!

By the way, Dick, way to show family sympathy when your aunt is describing the (apparent) death of your uncle. "Oh, yeah. Uncle Walt. I had forgotten he ever existed and died tragically. Shrug."