The reason that gums recede as we age is due to and often the result of wear and tear or years of aggressive tooth brushing.
Receding gums can also be caused by periodontal disease which can occur as we age.
Not every older adult has receding gums but it can happen and can be a normal part of aging.
But make sure you take care of your teeth often and brush often but not too much and make sure to floss and gargle with apple cider vinegar or mouth wash.
Get regular dental check ups as well and if possible have professional teeth cleaning done as it will keep your teeth healthy and may prevent receding gums as you age.