Basically what Jaseoffire said. Are there still unlabelled items? Sure. Are they finally actually working on fixing it? Yes. I've been extremely critical in the past when it came to their promises and the way Discord looks, but I have also used it now for over a month more or less daily without too significant problems.
Can it be improved? Definitely. Is it usable? Yes.
I do want to say though that I feel there is a difference between usable and accessible though. Having to memorise a bunch of unlabelled buttons falls under usable to me whilst having a bunch of properly labelled ones would fall under accessible. Discord is starting to move towards the latter though, and personally I feel we should try to be positive about it now that they're actually doing something.
Headings in messages are back, the buttons for leaveing voice chats and opening your user settings are visible and working and apparently file names show up again. Considering the fact that they "broke" the messages last week I'd say the fix has been quick.
Blindndangerous, I think it was, posted a list of hotkeys and an overview of the app in one of the other Discord topics on here a good while back. That certainly helped me figure it out a bit better, so I'll recommend people take a look at that if they haven't already.
That's all I've got for now, just thought I'd pop in with my two cents.
To see a world in a grain of sand, and a heaven in a wild flower.
Hold infinity in the palm of your hand, and eternity in an hour.
William Blake - Auguries of Innocence, line 1 to 4