By combining the ideas of endangered languages and constructed languages, I’m sure some people instantly get a bunch of ideas in their head. Maybe visions of discouraging Navajo in favor of Esperanto, or the most common, “people who are studying or creating conlangs *should* be studying dying languages instead.”
I see things differently. Conlanging is the solution, not the problem, especially to the dead and moribund languages. Conlanging is not a solution to any challenges that Navajo might face. Navajo’s speaking community merely needs to keep speaking. They don’t have to rebuild a language community from scratch. They don’t need to speak a language from a necessarily incomplete and imperfect specification– the specification for Navajo is alive in peoples heads right now.
The idea that “you should study Endlangs instead of conlangs” implies that it is specifically the conlanging behavior that is the problem, or that someone who has the resources to learn Esperanto or create toki pona somehow could have used those resources to document, learn or promote a currently endangered language. A conlanger has a internet connection and spare evenings. A field linguists has all year, every year and a travel budget. They are not inter-changible. Cry for the field linguists spending their days teaching High School French instead of documenting Koro, not for the conlanger hobbyist learning Na’vi.
Completely Dead Languages
The language might exist only as a word list, maybe a translated bible and a reference grammar written to subpar standards.
The language might exist as a reference grammar and dictionary. Depending on how well done the reference grammar is, it is revived language might be a fair representation– some time traveller might comprehend the new language. Or it might be something similar, but different enough that no time traveller could understand it without serious study. In any case, all but the most talented language students end up speaking a simplified version of the language specification. All the modifications make the resulting revived language something like a conlang or a creole– (more the former because some people think a language isn’t a creole unless it was the result of slaves talking to each other on a plantation, or some such similar cultural situation).
There may be descendants of the last speakers of this language. Often they are the most motivated to learn. Be polite to them should you ever run into them. More likely, you will never meet these people, or they will have neither the talent, time or interest in doing anything with the language.
The likely fans of a revived completely dead language are likely to have the same characteristics and distribution of conlang fans. They will be mostly polyglots, many language professionals (translators, linguists), language hobbyists, above-average in language talent and motivation to learn a randomly selected language and evenly spread out across North America, Europe, and SE Asia.
The Moribund Language
In the dying phase of a language, it simplifies and begins to acquire features of the language that is overrunning it. The number of dialects drops a lot. So when a single revivalist has plans to revive the language, they have to decide what dialect to speak.
Depending on geography, you could possibly meet some of the last speakers. Still, it’s unlikely. If you do meet them, who knows if they have the time and interest to teach the language to you. In any case, be polite. Since the moribund language was recently spoken, the genetic descendants may still be around and may care about what you are saying about their language. Again, at least be polite.
Will speaking or reviving a dead or moribund language right the wrongs of a lost people? Probably not.
Will speaking a dead or moribund language save a tribes culture? Not really Who ever picks up a dead language owns it. They can’t help but speak it in the context of their own culture. Unless they are historical re-enactors, in any context in which they use the language, they are living in their own contemporary culture. The past is gone and short of a time machine, we can’t bring it back.
If we can’t bring back a lost way of life, why bother? Because these dead languages contain in them an irreproducible way of translating reality into words, which may have important application to psychology, philosophy and many other social sciences. And it is a entertaining recreation and a work of art in its own right.
Will a revived language be the same? No, but Navajo won’t be the same in a generation either. They all are constantly changing.