Yes, let’s forget that Franz Joseph’s blueprints were used to (mis)represent the refit in Star Trek III
Why?
The
Enterprise was rushed through refit to intercept
V'ger. It's not at all unbelievable that a display interface that would be activated only in circumstances that quite possibly never occurred in the interim* and that in any case did not itself require metrical fidelity might get "left behind." It was actually the class ship representation, as one can tell by the registry number, and not specifically a graphic of the
Enterprise herself [
https://movies.trekcore.com/gallery/thumbnails.php?album=401&page=2]. In universe, it's possible that during the refit a place-holder schematic was inserted into the security subsystem for certain types of alerts, and it was never looked at again, because an officer had marked the schematic as adequately set during the launch prep. Metrical fidelity would be more necessary in the quarters plan in the second graphic, so we can conclude that the follow-up graphic is more likely supposed to be accurate (whatever its source IRL, which could well be FJ, I've not checked, doesn't matter that much).
Admiral Morrow said that command felt the
Enterprise had had her day, and perhaps there was good reason that he and they believed that the best course of action was simply to retire her. There being computer code and corresponding data in need of an overhaul believably could have been one of those reasons.
* - And, yes, in case you're wondering, perhaps to the subsystem, this type of breach was classified differently than when the Ilia probe came aboard.