Do you even think there is still any kind of development ? They "release" stuff that was already there.
I mean look at the numbers, steam averages like 60-70 players and around 120 peak (I know I know, steam is not all but it's a good indicator).
There is no financial initiative to develop DU at this point. Forget about the server costs, whole steam playerbase can't pay 1 good dev salary. Moreover, DU has a very negative outlook for players who left for one reason or another and it's harder to "bring people back" then just go on and create a new game (probably taking and burning another kickstarter money due to incompetence).
There is that other game that is relatively similar, it has the same steam player numbers and devs there said they "postpone development indefinitely".