For me the thing that atrophied basic math skills wasn't the calculator, which was invented decades before I was born, but the rise of the smart phone.

Sure, calculators are useful in professional life and in high school math and sciences. But you still had to do everyday math in all kinds of places and didn't always have a calculator at hand. The smartphone changed that

I feel that's relevant in two ways: just like with math, a little bit of manual coding is going to be a huge difference compared to no manual coding, and any study like the one you propose would be hugely complicated by everything else that happened around the time, both because of smart phones and the coinciding 2008 crash