if the first game is any indication, it'll be expansion updates that may require a reset, i remember when they added the pond in it didn't need a fresh start, same with the trash bags, yet bigger areas, ie. The sandbox, upper yard, picnic table did need a fresh start as they altered the game world. So if we go by that my guess is AXL's arena probably won't need a fresh start. But considering, unlike the first game, you can't explore out of bounds areas, its probable that was done to avoid constant fresh starts