Fixing the soundmixing is very easy. The issue lies in the acoustics. I've linked a vid that may provide insight on the science behind sound:
The long and the tall of it is that the human ear is better at hearing sounds from certain tone ranges that it is from others, which is why we can hear an opera singer's voice over the orchestra during a live concert. In a normal soundmix, the vocals are put in a key our ears can hear better, while the music isn't. Our brains then select the vocals as the most important sound, giving them prominence when we listen.
For *some* reason, the soundmix of the Kemama revamp switched the vocals and musical score around in terms of their wave frequency, which causes the latter to overpower the former. This will not be an issue in Rotterdam though, where the soundmix is thoroughly practiced during rehearsals.
There's really no reason to panic. Kemama is quite safe, still.