[2] Some poorly known extinct languages, such as Gutian and Cacán, are simply unclassifiable, and it is unlikely the situation will ever change.
Extinct unclassified languages for which little evidence has been preserved are likely to remain in limbo indefinitely, unless lost documents or a surviving speaking population are discovered.
The obvious similarities are therefore now thought to be due to borrowings from Maba, which is the socially dominant language in the area.
Mimi might therefore be a language isolate, or perhaps a member of some other family related to Maban in the proposed but as yet undemonstrated Nilo-Saharan phylum.
It would be easier to address the problem with better data, but no-one has been able to find speakers of the language again.