Both ReMIXs released in the West around a year after their initial announcement. With 1.5, it was announced in September, and came out the following September. With 2.5, it was announced in October, and came out the following December. So, I'm going to go with September 2016 at the very earliest for 2.8's release.
DDD HD shouldn't take them too long, but seeing how it seems pretty evident by that stained glass Station of Awakening that Chi Back Cover will also be rendered in the Kingdom Shader, that's two out of 3 titles using the shader. And that's going to take a lot longer, particularly 0.2. So, I'd be happy with a September release, but I wouldn't be surprised if we get a repeat of 2.5 and get it in December.