Phabricator itself imposes a threshold that it won't display languages with fewer then 512 translated strings in the language settings.

The current situation, where for big groups like "Phabricator: Arcanist -> Core" you have to translate 600 messages before any appear, is needlessly punitive and means that even for languages like T299694 where someone requested the language be added, 2000 messages have been translated on the translatewiki side but only the ~100 of them that happen to be in small message subgroups happen to have made it to the translations repo, is arbitrary and unhelpful.

At the very least, the export threshold should apply to the whole Phabricator group, and be set somewhere lower than 25%. Since manual effort is required (almost always by me) to enable a new language on the Phabricator deployment anyway nothing would go wrong if the threshold were removed entirely.