Wilhelmshaven as a warning for Pearl Harbor

How much harder would Pearl Harbor be for Japan if the US Navy had studied a successful Wilhelmshaven carrier strike?

The precedent would make weak base defences harder to justify, although the reply still allows for underfunding and leaves the particular precautions open.

A successful Wilhelmshaven strike would give American planners a concrete example of a fleet losing half its strength in harbor. Claims that a base was secure would have to confront that precedent. The counterfactual therefore gives a much stronger reason to prepare against carrier attack. Funding could still fall short, and the particular defensive response is left open.