I must respectfully disagree - kind of.... language retention may indeed be used as an "elective" requirement, but it's not an absolute requirement:
The second requirement (b) “Community” has, in part, the following:
(1) The petitioner may demonstrate that it meets this criterion at a given point in time by some combination of two or more of the following forms of evidence or by other evidence to show that a significant and meaningful portion of thepetitioner's members constituted a distinct community at a given point in time:
There are 11 items to chose from, the one pertaining to language is:
(vii) Cultural patterns shared among a portion of the entity that are different from those of the non-Indian populations with whom it interacts. These patterns must function as more than a symbolic identification of the group as Indian. They may include, but are not limited to, language, kinship organization or system, religious beliefs or practices, and ceremonies;
(2) The petitioner will be considered to have provided more than sufficient evidence to demonstrate distinct community and political authority under § 83.11(c) at a given point in time if the evidence demonstrates any one of the following:
There are 5 items to chose from, the one pertaining to language is:
(iii) At least 50 percent of the entity members maintain distinct cultural patterns such as, but not limited to, language, kinship system, religious beliefs and practices, or ceremonies.
Language retention can be used (and for some Tribes/Nations often is used) to satisfy these elective requirements; but language retention is not absolutely 100% necessary for federal recognition. As I mentioned, there are several federally recognized Tribes/Nations in my area where (unfortunately) no one speaks the language (though efforts are being made to revive them). They’ve gained federal status by satisfying other elective requirements.
The second requirement (b) “Community” has, in part, the following:
(1) The petitioner may demonstrate that it meets this criterion at a given point in time by some combination of two or more of the following forms of evidence or by other evidence to show that a significant and meaningful portion of thepetitioner's members constituted a distinct community at a given point in time:
There are 11 items to chose from, the one pertaining to language is:
(vii) Cultural patterns shared among a portion of the entity that are different from those of the non-Indian populations with whom it interacts. These patterns must function as more than a symbolic identification of the group as Indian. They may include, but are not limited to, language, kinship organization or system, religious beliefs or practices, and ceremonies;
(2) The petitioner will be considered to have provided more than sufficient evidence to demonstrate distinct community and political authority under § 83.11(c) at a given point in time if the evidence demonstrates any one of the following:
There are 5 items to chose from, the one pertaining to language is:
(iii) At least 50 percent of the entity members maintain distinct cultural patterns such as, but not limited to, language, kinship system, religious beliefs and practices, or ceremonies.
Language retention can be used (and for some Tribes/Nations often is used) to satisfy these elective requirements; but language retention is not absolutely 100% necessary for federal recognition. As I mentioned, there are several federally recognized Tribes/Nations in my area where (unfortunately) no one speaks the language (though efforts are being made to revive them). They’ve gained federal status by satisfying other elective requirements.