There's always room for speculation mate, you could think "they went bald at an old age so their male pattern baldness must not be that aggressive" or "they were old so the cell/hair growth is also stunted by old age". No need for futher speculation, just wait and see how this goes. Wounding will surely be a big part in regrowing hair.
Atleast we know it works, just maintaining existing hair would mean nothing since some people just stop balding without treatments.
Disagree with that tbh, maintaining side free would be a great thing imo