The line about the Universal Translator isn't wrong, it's not enough information. Let's say the Translator's version is formal to a degree the Klingons will identify as Starfleet Normal. Even if they follow this suggestion:
The real question is, would they have known that on set/while writing the script at the time?
the Klingons will know it's the Starfleet patented Universal Translator providing the translation, and Enterprise is a sitting duck. Thus, they need to get the books out and translate by hand, as it were. Scotty pointing that out should have contained a reference to needing the books instead, and that's why the line and following scene is clunky.Yeah Uhura could have muted the comms, had the computer say the line, switched comms back on, and repeated the line. It's even a Galaxy Quest in-joke.
The real question is, would they have known that on set/while writing the script at the time?