I'm not sure I follow that reasoning.

In Feist even copying made-up entries designed to detect copying was deemed to not be an infringement.

The statement that "this area is assigned to this timezone" is not a creative decision. It's an assertion of a fact. Even if it's a false fact made up by the author, it's still an assertion of a fact.

That information is not subject to copyright.

Perhaps the particular expression of the information is.... but I'm not sure how the tz database infringes on that.

Am I missing something?