Uhura does get her memory wiped at one point in TOS and has to relearn English so perhaps she never relearned Klingon. Saying that, I’m happy to ignore the TUC scene too.
One thing that does bother me about JJ Uhura and SNW Uhura is that her language abilities feel so over the top. No one Uhura’s age is going to speak 37 languages, unless they are being very loose with what can be counted as “speak” (e.g. have a basic conversation vs fully fluent).
If you’re a native English speaker possible to get to a reasonable level in an Asian language in a year with dedicated study and the more languages you start with, the easier it will be to pick up more. But 37 languages, including non-Earth languages, when Uhura is still a cadet is ridiculous, even if Uhura is supposed to be gifted. Not only for the time to learn each language but the daily maintenance to not forget one.
In the beta canon, McCoy is able to learn Vulcan quickly using implants but if such rapid language learning technology exists in the alpha canon then no one would be impressed with her language abilities.
I know The Enterprise is the flagship and so everyone is top of their class but it still needs to have a level of realism.