I thought Yoshi P answered this at Fanfest in an interview, then looked and he did. He said we can go across shards with the Echo, something even Elidibus hinted to in 2.1 when he hinted that the Echo gave the almost the same power as Ascians have. Yoshi also said it will be explained in the msq.

I personally think it has to do with learning more about the echo and using it similar to how the Ascians uses their powers to go across shards.