SO If you think about it the reason why human head hair does not cease growing is rather obvious. FOr example a cats hair stops growing after a certain point or at lease does not go beyond a certain length depending on what cat type. The reason why head hair ceases growing could only be that as a result of the habit off cutting head hair by humans when the genetic mutation occurred where head hair doesn't stop growing it was not deselected on account of it not causeing problems as a result of hair cutting.
Now if we look at this we can see that it is then quite possible that in the future as a result of shaving armpit hair and leg hair if a mutation occurs where women's hair in those locations does not stop growing it will survive naturally and be spread through the population by procreation eventually to the extent to where women will have to shave to not look like hairy legged beasts... so in other words the act of shaving is likely going to result in the necessity of shaving...
