It has been done earlier; multiple times, by every serious manufacturer. :-] The real difficulty lies in: 1) Noise in the on-turbine wind speed and direction

It has been done earlier; multiple times, by every serious manufacturer. :-] The real difficulty lies in: 1) Noise in the on-turbine wind speed and direction measurements and/or robustly (see point #2) operating LIDAR or met masts in front of the farm to try to avoid said measurement noise. 2) Actually arriving at a robust, operational in real-world conditions, fully closed-loop control system. A commercial wind farm has to operate 24/7 for 25 years without a bunch of engineers and scientists babysitting it, which is what is likely to end up happening if the cool control system relies on offline simulation results, topographical data, and/or human-supervised calibration & tuning. It's not all doom and gloom: Ongoing improvements in sensor price/quality will probably make these kind of global control systems more and more practically feasible in the future.