Where I work, we just upgraded from VS 2013 to VS 2015. One of the new things in VS 2015 is a light bulb thingy like you describe.

I have yet to see the light bulb *ever* offer the correct suggestion. Each one of the suggestions has always been something which would have had the same kinds of terrible ripple effect in our code that you described in your anecdote. Luckily none of our interns has ever taken any of those suggestions. Yet.