It is allowed to use whatever languages you want, however, if it is produced (recorded) outside the USA, regardless of the languages used, or if it contains non-English language content regardless of where it was created, it will be subject to approval by DISHWorld if you want to publish to the USA and Canada. Otherwise it will restricted to publication only in UK, Ireland and Rest of World unless DISHWorld grants a waiver.
This applies to both public and private channels.
- Joel