If I have to give an estimate on anything I work on, I tend to overshoot. I feel it is more respectful to prepare people for a longer wait in the case that any issues arise.
From the sounds of it, SureAI has ALL the vocal work done, All the visual cues (signs,posters, etc.), the subtitles and even an English launcher built.
The big task now is for them to go through the game again and ensure that each of those thousands of lines of dialogue are in the right place. This is probably why the completion date of the english translation cannot be given. If all the voices are in the right place then we should see this soon.
As a music producer, I know what it's like to have a "finished" product only to find something that was supposed to be changed. It takes time to find mistakes but we will have a much better experience after the wait. Im sure of it
EDIT-- Misread the launcher part =D, that still needs to be done it seems