" ..putting money into the preservation of native languages would be a concrete gesture that could produce equally concrete benefits..."

Well - the money would be appreciated and spent by the language police - but guaranteed without any permanent benefit to the FN - merely preserving isolation and hopeless life style of frustration.

Being multilingual and having been around the globe more often than I wish to count - my experience:
- English is the language of busines, technology, logistics, documentation .... No matter whether you are in China, Japan, Europe .....
- Translation beyond the superficial - involving deep cultural context - is tricky, very expensive and of limited availability. Technical translation is not possible for languages that have not evolved in terms of the Industrial; Revolution and its consequences.
- For any language group to survive requires a critical mass of speakers and their economic independence. My guess would be a minimum of 100 Million + population.