This article by TVO gives a concise explanation of the issues with Metis Nation of Ontario claims to legitimacy.
https://www.tvo.org/article/what-is-the-metis-nation-of-ontario-and-why-is-it-so-controversial
https://www.tvo.org/article/what-is-the-metis-nation-of-ontario-and-why-is-it-so-controversial