This is a good point, and it makes me realize I phrased my question wrong. Whatever we choose to do won’t be too technically hard.
The big picture question is, what should be our translation policy for the large number of Reference Application modules that are community-owned?
Do we want a workflow where reviewers for each language must review translations? (What happens for uncommon languages, e.g. when there’s basically just one person doing all the translating? How does someone achieve the trust level to be a reviewer?)
The “least work” approach work would be to (a) let people be language reviewers if they want, and they’ve reached a certain trust level, but (b) automatically apply translations as they are done anyway, without review, and (c) make a concerted effort to review translations around the time of our twice-a-year Reference Application releases, as part of the release manager’s tasks.
The “more correct” approach would be to (a) have reviewers for each language, (b) automatically apply only reviewed translations, (c) make a concerted effort to ensure all translations are reviewed around release time (or more often), and (d) find an i18n manager to coordinate this.
Do we have anyone interested in being the OpenMRS i18n Manager? 
Until someone steps up to do this, I’m afraid we’ll have to go with the “less work” approach.