The FPVLR mod would be cool. Can only see a benefit with follow-me once elevation has been added to the equation. I would love to vid some snowboarding or mountain bike riding but unless the drone can change its elevation as it fly's it kinda pointless. Not sure that the software is developed yet, although AirDog look to be getting close, time will tell when it eventually gets past the Kickstarted stage and we can see it operating.
I think the lack of follow me might be due to FAA LOS guidance. I have follow me available with my 3DR Solo and it works very well. I never use it. I played with it a few times but quickly realized it's a feature you think you're going to use but rarely do. Not having direct LOS and control of your drone is unnerving. Battery life, while getting better on some drones, is still too short to get your drone up and locked in and still have time to perform whatever activity you want to be followed for, and then re-establish control of your drone to fly to a safe landing. Add to that the constant checking you end up doing to make sure the drone is still following properly and it's just not worth it. Of course, you can just take off and rely on the drone auto landing with GPS, but all drones can, and do, lose GPS time to time. Not having your hands on the controller when this happens is not a situation you want to be in.
Will GoPro add it down the road? Probably, just based on the amount of request. Do people really need it? Probably not as much as they think. Just my opinion.