Supposedly 1-2 million people speak Arakan, so I doubt it's very difficult to find enough moderators. It's likely not worth the effort to do so unless regulation forces you to do it, however.
1. Moderation jobs tend to require a 4 year degree, which is hard to find in a region with a 75% literacy rate
2. Requires incorporation in that country. Try opening a FB office or contractor in Myanmar during an active Civil War
3. (Speculative) Hard social faultlines exist. In Rakhine, society was communalized into Buddhist ethnic Arakan - Muslim ethnic Rohingya and Bengali - Hindu Bengali and Arakan. All ethnic and religious groups spoke Arakan, but all were diametrically opposed to each other due to the communalized society that developed.
This is just one example from the Rohingya Genocide, but there are sadly dozens all over the developing world.
For example, when dealing with the Tigray war like in the article above, you'd need to moderate for the 100+ languages spoke in Ethiopia, Eritrea, Somalia, South Sudan, and Kenya (all regions with ethnic fault lines that extend into Ethiopia).
This is a problem that can only realistically be solved by AI (as it's an intent polarity problem and a Machine Translation problem), but these are less sourced languages with limited corpora or knowledge.
All of this is known btw. This is why Google, Amazon, and Meta hire hundreds of linguists in India and Chinese companies like Tencent, Baidu, and Ant hired similarly within China to work on MT and Polarity in South Asia and China respectively, but a similar effort hasn't occurred in Africa and most of ASEAN yet.