Since it's been 3 months since the last announcement, another update is in order.
What's been completed for the Legends Overload expansion so far?
So far, the new story events, the models, the maps, the textures and the animations have been finished -- essentially, all of the new story content.
What's left for Legends Overload work?
Coding -- Most of this should be straightforward and will likely not take too long, as a lot of the work is primarily already-created content that fits into already existing game/engine mechanics. The primary exception to this will be the new gameplay mechanics of the new modes, which will require a little extra work.
Testing -- This will end up being the longest part of what remains, just due to the large quantity of tasks within it, including models, animations, maps, new passive abilities, new Legend Plus difficulty, new mechanics, old and new save files, and so on. Testing taking a long time is nothing new, but it's the biggest thing out of what remains.
Release/marketing -- The release of Legends Overload, as well as any media and information on new modes, will likely all occur at the same time and will likely come suddenly and out of the blue. November is currently the likely point of arrival for Legends Overload, but that depends on how smoothly testing will go.
Is there any other news regarding Legends Overload?
Yes, a new mechanic involving a new pseudo-party member who can be customized to some degree is going to be added -- this was previously unmentioned in past news, due to it being planned and worked on very recently. This new character will NOT be one of the three new playable characters that are planned for future expansions, but they are intended to have availability in Story and Endless Dungeon and are planned to be available at almost all times in any party when recruited (called by the player into battle directly).
Similarly to the two new gameplay modes, more information on this character will be made available around release.