It can absolutely happen. Our body is capable of healing itself if we give it the right tools and the right environment for it. The thing is people have different deficiencies/toxicities (emotional toxicity too) which contribute - so what might work for one person may not work for another, and this is what makes finding solutions difficult. Someone might say mineral x or vitamin x, or solution x cured my hair loss, and that might be very true for them, but that might not work for others because ultimately everyone is different.
But, from what I have seen, red light therapy is meant to be good for hair regrowth and I believe Analyze and Optimize have posted some interesting studies about this on their Twitter recently. Morning and afternoon sunlight contains a lot of this spectrum too, so make sure you're getting some sun exposure.