It is speculated by some that alternate worlds such as the Twilight Realm and Termina may be unaffected by the timeline split. However, while these two realms are alternate dimensions, there is no evidence to support the idea that they exist outside of linear time. Both realms have demonstrated the ability to receive beings from the Child Timeline and return them to the Child Timeline when they exit back into Hyrule. There is no reason to believe that these two realms would only exist as a single timeline, or that they could "prioritize" inputs from one timeline, and later output these into both the timelines.
In addition, the renowned Youtube show, Game Theory, dismissed the Zelda Timeline, particularly the Defeat Timeline (in where Link fails on his quest) on the grounds that "the hero cannot be simultaneously victorious and defeated". Elaborating, he explained that with Link defeating Gannondorf, two perfectly possible timelines are created; However if Link dies at any point in his journey another separate timeline is created. Explaining that the only way for all 3 timelines to exist is the Many Worlds Theory (the theory that all possible pasts and futures exist in separate timelines).
Thrill Digger AreaEdit
"This is the Thrill Digger area. It is a game run by a Mogma called Tubert. It appears as though there is another Mogma here. There is a 95% chance that he has some information." — Fi The Thrill Digger area is a cave that appears in The Legend of Zelda: Skyward Sword. The entrance located behind a bombable wall between two huts in a Bokoblin camp in Eldin Volcano. As its name implies, it is where Mr. Tubert's Thrill Digger mini-game can be played. Besides Thrill Digger, the cave features Rupee Ore on the walls of the cave, which Link can shoot to make them drop Rupees who value is based on the color of the Ore. However hitting Black Rupee Ore will drop Rupoors. There also a few digging spots around the fenced in game area. Link can also chat with Mr. Tubert by sitting on the chair near him (which is useful for healing Link if he takes to much damage from the Bomb Flowers in Thrill Digger). If Link asks him all three available questions then quits talking, Mr. Tubert will tell Link about the Rupee Ore found in his cave. There is also a stone tablet near the exit which Link can read to receive a helpful tip on playing Thrill Digger.
Besides Mr. Tubert, there is also another Mogma named Zanc appears in the back of the cave and will offer Link a hint on how to win at Thrill Digger in exchange for 20 Rupees. Later in the game, Link can play the Goddess's Harp near a swarm of Blessed Butterfly to summon a Gossip Stone.
Rupee Ore MineEdit
The Rupee Ore found in the Thrill Digger area may explain where all the Rupees (and dreaded Rupoors) in Thrill Digger come from. It also may indicate that at some point after the defeat of Demise it may have been mined for its valuable Rupee Ore. If Eldin Volcano eventually became Death Mountain (possibly due to it becoming less volcanically active), then most of the Rupee Ore may have been mined out (due to the lack of Rupee Ore on Death Mountain), yet some of it remained in smaller quantities inside the rocks for Death Mountain, which when the rocks where broken open turned it Rupees. This would explain why Rupees can often be found by breaking the small rocks on Death Mountain in Ocarina of Time.