For me sensitivity has rapidly reduced. I had A1c of 5.3% 6 months before and 90 fasting sugar, then I got A1c of 6.1% but fasting is still 94mg/dl , so was not officially diagnosed prediabetic.
But I know I am and I feel I am getting worse at a rapid rate. And no, for me I am unable to get to my previous sensitivity level. Even though I have caught this insulin resistance very early and been on keto diet, my sensitivity is not back to normal.
I am still hopeful and trying to get the sensitivity back.
I suggest you to try, because if you try to get atleast you will have a chance to get it back, but if you don't try you will never.