I managed to obtain file hashes to English preload and compare it to my Russian preload I downloaded from Origin
The only files that are differ files in __Installer folder(of no importance, probably contains list of files to delete on uninstall), files in Support folder (also of no importance, just docs in different languages) and most importantly files in Data\Win32\loctext folder: en.sb, en.toc for English version and ru.sb, ru.toc for Russian. The files hve approximately the same size and are to small to contain text localization.
After checking those files in text viewer I noticed that they contain only paths to actual localization files:
win32/loctext/en/text/da3/layouts/multiplayer/mporlais/mporlais01/mporlais01
da3/loc/texttable/en/da3/layouts/valroyeaux/val_blackwall_prison/val_blackwall_prison_win32
Those files are not present in preload and I believe they will only become available after the game launches in 3 days.
I hope copying those localization files from English version will be enough to play the game in a way it was intended instead of playing with butchered translation(I had bad experience with Russian DAO and i don't want that anymore)