"over night" statement is a figure of speech....
I am sure that as soon as they caught wind of what vega FE was capable of, they would have been doing everything to improve their cards but again that is what, a few months at most despite people who own the cards and use them for such tasks that have been complaining since the gpu was released? And again, a 300% improvement in a few months at most? Yeah ok....
As uber said, it more than likely had the features disabled from day 1 in order for those who really needed the extra power for such tasks to cough up even more and get a quadro card but with the vega fe etc. coming out and spanking the titan xp for pro work, nvidia had no choice but to enable features/improve the gpu. That is how competition in the business world works.
If you want to believe that nvidia had been working on that from the start and that the 300% improvement update just happened to come out right after vega's release then be my guest
Also, don't people on here say about how nvidia are the best because you get the full performance on day 1 i.e. no having to wait around for months in order for the gpus to perform as they should have on day 1??? If it took nvidia this long to get 300% improvement then my goodness, they make AMD look godly in the driver department....