That map change is a town takeover, adding a prowler enclosure to World's Edge where you'll find both antagonistic animals and high-tier loot. The Old Ways also offers a series of challenges you can complete to unlock new cosmetics, two of which are recolored versions of skins that were previously available during Season 1's Legendary Hunt. In fact, all the cosmetics from that event can be obtained during The Old Was if you missed them the first time around.
The game overall will see some changes outside of the event. Apex Legends is permanently adding duos as a game option, and you'll also be able to choose to drop on either World's Edge or King's Canyon. There's more info on all of this in the video above.