Symphonic does allow for foreign languages.
You can select the language field when creating the release via a drop-down box to at least tag the release properly. You can create a ticket via our portal and we can advise your situation. We can't guarantee that all partners will accept your music in a foreign language and are working to improve this to accommodate various territories.
We need the English version, Simplified Chinese and Traditional Chinese translation of all fields that can be written as such (artists and titles). Please submit a ticket for this when setting up your release so we can appropriately address this.
We don't have Cyrillic fully supported in our system yet. We are working on extended language support it and it is nearly in pure working order.
Another issue is that most partners don't support Cyrillic or have a hard time ingesting it.
Also iTunes is very strict on their translations and you would most likely have to provide the English translations for those releases to be sent to iTunes. On top of that we may get very strict or even stop the delivery to iTunes if any tickets start to arise with that content since that negatively impacts us and other clients.
We will fully roll out full language support but currently it is in a weird limbo state and we have to treat each request like this a special case.