Age is just a number for Floyd, he is still active in boxing but not in professional boxing, its in his gym. No way he will loss against a youtuber, unless he will try to create something that will lead people to be interested in the 2nd fight, but that would be a dumb idea as I know Floyd does not want his undefeated record to be tarnish.
but aging can never be avoided and of course it will all make Floyd's golden age a fondest memory and a story for his grandchildren that he was once a great boxer, Floyd's record will be beaten by young boxers someday and he must give up that.
He can make his own story, he can say he is an undefeated boxer but not the greatest boxer in his generation. If there's a debate, I think Manny will get more fans over Floyd as Manny is a real warrior who fight anyone you put in front of him.