In my opinion Histogen pics were pretty impressive, despite the slight difference in lighting and angle between the "before and after".
Their data showed not only regrowth but an increase in overall thickness.
Remember those results were after 3 months only and from only one round of injections at a very safe dosage.
I think that if it works for "normal" vellus hair it might work for Follica's vellus hair too since that's nothing but your natural hair being forced to grow.
And we will also have Replicel that will do the same thing (make vellus hairs go terminal), with a different mechanism.
Yeah, it's all speculation but in my opinion we have good chances a combination of these (or even one of these treatments alone) will work extremely well.