It's 12 a.m. for me, so bear with me on this, but... here's a theory of mine.
In the Nintendo Treehouse video from E3, I noticed that they mentioned that the player earned Nook Miles from their journey to the island at the beginning of the game.
I theorise that those same Nook Miles can then be earned from traveling off island to other places. For example, a smaller island containing stores, or other player islands. Bottom line: traveling off island is encouraged, and thus, we can expect this to be a feature.
In the Nintendo Treehouse video from E3, I noticed that they mentioned that the player earned Nook Miles from their journey to the island at the beginning of the game.
I theorise that those same Nook Miles can then be earned from traveling off island to other places. For example, a smaller island containing stores, or other player islands. Bottom line: traveling off island is encouraged, and thus, we can expect this to be a feature.
-bows-