It doesn't. The division of labor does not end. That is a misconception. Read the quote more carefully.

The "enslaving subordination of the individual to the division of labor" ends.

When Marx talked about the "division of labor," he usually had in mind the enforcement of the division of labor, i.e. that society has mechanisms that force you to remain in a single specialized field and make it unreasonable for a person to branch out and do more stuff. You may work on the same part of an assembly line your entire life and be trapped in it.

One of the reasons is that labor in a society with scarcity is "only a means of life," meaning, you do it purely for survival, and so this makes it difficult to consider quitting a job or learning new skills as you can starve in the interim. In a post-scarcity society, you would not need to labor to survive, i.e. labor becomes "life’s prime want," meaning you do what you do because you want to do that. Nothing would tie you down to a specific specialized career.

For as soon as the distribution of labour comes into being, each man has a particular exclusive sphere of activity, which is forced upon him and from which he cannot escape. He is a hunter, a fisherman, a shepherd, or a critical critic and must remain so if he does not wish to lose his means of livelihood; while in communist society, where nobody has one exclusive sphere of activity but each can become accomplished in any branch he wishes, society regulates the general production and thus makes it possible for me to do one thing today and another tomorrow, to hunt in the morning, to fish in the afternoon, rear cattle in the evening, criticize after dinner, just as I have in mind, without ever becoming hunter, fisherman, shepherd or critic.

Critique of the German Ideology