The W3iL mappool consist of mostly official maps. Those are beeing used for all matches of the league.
The 2v2 maps Featherville and Hellfire Plateau are created by Mr.Henci. They can be downloaded here.
The Teammanagers are forced to always host the official versions of those maps. Whenever there is an update, the admins will make sure to inform all involved parties.
The maps must be saved in the download folder, which can be found the following path, unless it has been modified by the user (C:\My Documents\Warcraft III\Maps\Download).
If you as a viewer, would like to watch a replay of on those maps, make sure to download them as well, and save them under the given path.