how can it have more potential?Yea creating new hairs from scratch with stem cells is much more complex than just trying to stimulate existing ones. It's borderline science fiction, but also has so much more potential.
It will have the same downfall as normal hair transplants, they can't do normal/high density hair if they where to grow a full follicle and then transplant it. (not that i think that will be the method)
So if already existing hair transplants will thin out, what will make sure that stemsons hair transplant won't? And if we think of their "generic", then my guess is that it won't work. Just like other people who gets organ transplants, they are on immune suppression medication. That will be very expensive and take people in to high risk of dying of normal sicknesses and infections. - If we go with the full grown hair follicles transplanted.
That is why autologous stem cell transplants/injections are so much better, we are beyond all of this mentioned before.