I know exactly what is going on here. The left has been trying to stimulate the Indians to demand “Indigenous rights”, favoring Indians over Mexicans.
The background to this goes way back. It used to be that Mexicans claimed close to pure Castilian Spanish blood, to put on airs above the Indians. Practically speaking, until the 1940s, the legal difference between Mexicans and Indians was that “Mexicans wore shoes.”
Then the Mexican government devised one of the more complex means of distinguishing between races and mixed raced peoples this side of South Africa. Even mixes like Indian-Black-Asian were included.
But that, too, has kind of fallen by the wayside. So it comes back to “Mexicans ruling over Indians”.
The left hopes to take advantage of this long held grudge, and not just in Mexico, but in similar situations all over central and South America. To the effect of “Support indigenous rights! Take money from the rich people and give it to the Indians!”
So you can see why the Mexican government is keen to avoid this crapola.
Each Latin American country adopted different racial classification systems depending on the sociopolitical climate of the nation. Puerto Rico classifies anyone with white ancestry as "white" even though most folks on PR are mulatto to high-yellow (only about 1/3 can really pass as "white" per my last visit to the island). Likewise Costa Rica reclassified mestizos as "white" in order to attract more European settlers in the late 19th/early 20th century.
After the Mexican revolution "indigenismo" became the rage among the intellectual and governing elite. A noted sociologist named Jose Vasconcelos even created a ruling racial ideology based on "La Raza Cosmica" whereby the Mexicans were glorified as having the best of the Amerindian and the European in their bloodlines.
Mexico was probably the only Western Hemisphere independence movement (outside of Haiti) where true “natives” played a major role, unlike ours and the other countries of the western hemisphere born afterwards(European settlers versus European Government).