I wonder how he wants to go about it. Should those poor tribesmen forced to study the language against their will? In modern, connected world there is no reason to speak the "native" language, especially if there isn't a ton of literary works in it (I suspect there aren't.) A child today would be much better off studying and speaking one of major languages, instead of learning the language that only a handful of people understand.
Local languages arose because of isolation of tribes. Once the Internet comes into every hut, fluency in other languages becomes essential, and old languages are set aside. If linguists are so upset about such a natural thing, they should learn and speak those dead languages themselves, instead of foisting this task onto others.
WOW.
Snow is blowing so hard you can hardly see.
Now, about these lost languages ~ you can learn Ladino on the internet. You can also learn Mingo on the internet.
"So what" you might ask!
First, so you can understand what more than half of Jewish names mean, and Secondly, so you can understand Homer Simpson.