Were you earning Echoes on that character already? If not, according to the blue post on the changes, you start earning Echoes after completing the cloak questline.
Specifically:-
More Echoes
In our last update, we added Echoes of Ny’alotha, a new currency available from most Visions of N’Zoth content, which can be used to directly purchase Rank 3 Essences that have already been unlocked on a different character. We plan to expand the availability and purpose of this new currency. Now, once any character completes the legendary cloak questline, they will immediately begin earning Echoes of Ny’alotha from all of the usual sources.