This kind of change can easily cause regressions, while its review isn't easy. Considering the fact that there is no issue in the app, I don't see why we should do this.

I'm aware of this, but working with the code as it is is quite confusing. I tested loading other translations, it looks working fine all.

... is quite confusing

You'll easily get used to it after a while. It's much simpler than the main code.

Moreover, the GUI's order might be changed again later, and we don't want to make heavy changes each time.

Moreover, the GUI's order might be changed again later, and we don't want to make heavy changes each time.

I just think that the code filenames should respect what there are about. I don't think there will be much to reorder in future.

This kind of change can easily cause regressions, while its review isn't easy.

Apart from translations, what seems to be the problem? What kind of regressions do occur when changing class and file names?
The only thing that comes to my mind are signals and slots, but they are referenced without obsolete macros, so that should be fine as well

What kind of regressions do occur when changing class and file names?

Regressions could easily happen because we're fallible human beings.