While I have seen a few people complaining about this and it is not limited to exclusively Heart of Thorns, today I finished 100% on Verdant Brink on my character with 100% map completion. I did not get any rewards, which I was understandably a little sad at, as there is an item that I need for Hourlogicus that is supposed to drop as a Map completion reward. With a little investigating, I found out that I was supposed to receive items for 100% Dry Top, Silverwastes, and Southsun Cove as well, but never did. I have not tried this on a character that does not have 100% as I don’t have one.
Thank you!