Turns it it is a bit complicated and contested. The census asked people how they chose to self-identify, and in recent years it has become common for people of mixed-race who feel neither "white" nor "Indian" -- or who are accepted by neither group, or who may lack "status" under the terms of the Indian Act -- to adopt the Métis description. (The 2016 Supreme Court ruling called Daniels, which encouraged the mixed = Métis principle, is also a factor.)
Not everyone likes that development. “Mixed blood is far different than a citizen of the Metis Nation,” declares David Chartrand of the Manitoba Métis Federation, which rejects the census data.
As it happens, I've been reading Ens and Sawchuk on Métis identity and the Métis nation over 250 years. It turns out it has always been complicated. Ens and Sawchuk call themselves social-constructivist about Métis nationhood. They mean the Métis are not simply anyone produced from indigenous/non-indigenous interbreeding, but a nation which became one when it collectively defined and asserted itself and was seen as a nation. (Like any other nation, in fact.) Inevitably the nature of the nation keeps changing, but Ens and Sawchuk believe there are boundaries.
Ens and Sawchuk endorse, I guess, more-or-less "They are Métis because they assert themselves as Métis." I suspect they would be less keen on "I am Métis because I assert myself as Métis" -- which seems to lie behind the numbers on the 2016 census. Their chapter on the Métis of Ontario is sceptical; they primarily see the Métis as having been socially constructed on the Prairies since the mid-19th century. And they are not keen on the Daniels idea of Métis, either.
