Language documentation doesn't completely change the social environment, but can indirectly enhance the language's prestige, e.g. by devising a writing system that then gets adopted in education and media and by raising awareness that "different" doesn't necessarily mean "wrong". It also means that children who grew up without learning their parent's mother tongues but want to learn them later in life can use the material collected as part of language documentation for studying.
In response (our dialects having had an army) where before those countries had been taken as arbitrating the prestige forms of their languages, there's been a revival of local dialect. We don't have an "RP": politicians in 2020 will of course use a prestige register in speech, but don't bother to hide their dialects.
(Written language has an orthography, taught in school. But most people I know treat SMS/chat as an oral, not literate, form. In german this results in idiosyncratic spelling, in french, "langage SMS")
Too bad in France there was a policy of linguistics cleansing which effectively destroyed dialects and non-French languages as fast as in two generations. Of course there are other factors as well, like marriages in-between people of different regions.
PS. 3 bises > 2 bises ... but on the other hand, if it weren't for you all, we wouldn't have verlan :-)
PPS. https://i.pinimg.com/originals/6e/d4/b0/6ed4b0c84ac892dc5b9d...
> Enslaved people developed a hybrid language that sailed from Africa to the Caribbean and—unbelievably—back again.
[1] https://slate.com/podcasts/lexicon-valley/2020/09/the-englis...