In my observation, very few British doctors use the term cured either. As
@Brunneria suggests there are potential implications.
Personally, I also had one test at diabetic levels, then every other test well below the threshold for diabetes diagnosis in UK (48 for diabetes, prediabetes being 42).
In December 2014, my medical record said this:
View attachment 19047
I have also been removed from the practise diabetic register, but in so doing, I have agreed (very willingly) to continue to have annual HbA1c tests, due to increased risk of "un-resolving". I have also had two rounds of retinal screening since this action was taken; the latest being yesterday.
My stats are in my signature.
To be honest, as I suggested before, I doubt your doctor would be willing to change your status as yet, and I feel pretty certain they will never be willing to remove the diagnosis from your record.
I would urge you to be happy with your non-diabetic levels and keep up the good work.