As the instructions said that name is a property of the object 'Players', Also we can't target the name of the player unless we use the Key Value which is the name: the structure is like that :
Players[{name: "a"}, {name: "b"} ... {name: "z}];

Please do not forget to use spoiler tag next time.

As for your question: I am by not means expert here but I'd say it is indeed a common practice.

Every player (element in players array) is constructed into an object:

class Player {
  constructor(name) {
  	this.name = name;
  }
}
let players = ex_names.map((n) => new Player(n));

.name allows you to access and return the property value. If it would not be there you would return the whole object. For example Player { name: 'a' }

very cool!

i can't understand why are you using name