It would be odd indeed for a church to have an “official language” that none of it’s heirarchs read, write, or speak . . . while there may be some communications with Rome in latin, that wouldn’t make it the “language of record” for that church, any more than sending a letter in slavonic would make it official for rome . . .
You’re mixing up two different concepts here. What you are talking about is called a “working language”. The Church does not currently have an official working language, though Italian is widely used for the purpose. Other languages are also used, especially French, German, Spanish, and, increasingly, English at the international level, and various local languages at the local level.
Until Vatican II, though, the official working language was, at least on paper, Latin. That is why the sessions of the Council were held in Latin, in spite of the fact that by that time, few of the participants were able to speak or write Latin, and most were not even able to understand spoken Latin or even read Latin, at least to the degree necessary to follow the proceedings. At the end of each session, the proceedings were translated into modern languages that the participants could understand. If they had a response, they wrote it in their language, and it was then translated into Latin so that it could be read at the next session.
This proved to be so cumbersome that Latin ended up being discarded afterward as an official working language, even symbolically, for the very reason you wrote.
Nowadays, synods are conducted in “working groups” divided by language, with Italian speaking bishops working in one group, and French, German, Spanish and English speaking bishops working in their own groups. For general sessions, the documents are translated into (generally) Italian.
However, a “language of record” is something different. At the end of the synod, all of the final documents must be translated into Latin, and that translation is the authoritative version. Any disputes must be settled using only the Latin version, not the original documents it was translated from. The official Italian version is not the original version that was translated into Latin, but a back translation from the official Latin version. The same with the official translations into other languages.
This also holds true for synods in the Eastern Catholic particular churches. Their proceedings must be translated into Latin, and that is the only authoritative version.
Same with Canon Law. The Canon Law of 1983 was originally hashed out in modern languages, formulated in Italian, and then translated into Latin. If there is a dispute about a particular clause, then recourse must be made SOLELY to the official Latin version, and never to either the original Italian version, or to the official translation from Latin into other languages. This also applies to all of the Eastern Catholic particular churches, whose official Canon Law is written in Latin.
That’s what a “language of record” is.