Reddit mentions of Mountain Maidu Grammar

They mention all three dialects of Maiduan (there may be a fourth, but it's disputed).

Taylorsville is dead center in the Northeastern Maidu area; Golla states that there is considerable interest in revitalization of that dialect, and that it is well-documented by Shipley, a non-native speaker, and others.

At some point there was a split between people who want to spread the language and those who want to restrict it, that's my guess.

Edit: A book on Mountain Maidu Grammar, published this year.