From the source code it seems that Copay wallet (and therefore Bitcoin.com wallet) already uses or used Crowdin in the past for wallet localization. Maybe not anymore. Anyway, thanks for reply, I'll email them.
There are people willing to translate both Copay and the forked Bitcoin.com Wallet to their native languages. But project owners do not seem to communicate on Crowdin. How can a person contribute and translate Bitcoin.com Wallet then?