In that the soreness is due to how well our legs are conditioned for the particular effort, no not due to age.
But yes, it's due to age in part because the older we get, the harder it is and longer it takes for that conditioning. And the more quickly we lose it, unfortunately, because age also means that longer recovery is needed. So we'll get sore more often, for longer periods, when we push outside of the comfort zone. I don't think it's anything to be concerned about - as long as we can avoid injury, we just push through it after a day or two.