While a straight up assumption would be that this game comes in the "Hero's Defeat" timeline, and after A Link to the Past (Because of it's name and all), but I actually think that it would go to the "Hero is Successful - Child Era" somewhere near Majora's Mask events. Here's why:
- There is a Majora's Mask in a shop, but that's the obvious one.
- So somewhere near the stone tower temple, there are these blocks. As I recall, when you turn them upside down, you can see the triforce, but upside down. This could actually have something to do with the Lorule world from "A Link between Worlds", since an upside down triforce is also in that game.
- Also in Majora's Mask, Ganon is "executed", and with the whole Alternate-Ganon thing and the fact that Ganon never appears in that timeline again, could mean that Ganon will not be in that game. In The "Hero's Defeat" timeline Ganon is always revived.
However saying all this, we could also assume that Majora's Mask and Lorule exists before the timeline split (In times of OoT) and that it would also exist in all 3 timelines, thus the mask being simultaneously in MM and AlbW, and the upside down Triforce being in both MM and AlbW.