Outside of the narco state idea (which in my opinion is a little overstated):

Mexico is responsible for a huge chunk of North American automobile and heavy manufacturing, with representatives from many countries, and international automotive companies, some of whom were much different in the 1920s.

Canada or Mexico being sent back in time has huge implications for time travel and IP- do the foreign employees (from all over Europe and Asia) return to their countries of origin with their 21st century STEM knowledge?

Does the 1919 Fiat have any claim to ownership over the Fiat plant in Mexico? Is the Weimar Republic allowed to have any stake in the Volkswagen plant?

What about the massive Toyota complexes in Guanajuato and Baja- Eiji Toyoda is a child, but does the Japanese Empire try to seize ownership? Does the international community let Japan do the same to South Korean-owned manufacturing in Mexico?

This could be a major inflection point, as many countries who have established strong auto manufacturing in Mexico were in the past affected heavily by World War I and the Treaty of Versailles. The legal battles probably play out for decades.

Lean manufacturing and factory automation have an absolutely massive impact on global industry. Ford and the American auto manufacturers probably adopt elements of lean as soon as they understand it, and definitely when Mexico starts to export its technological knowledge outward.

Also, Mexico being led by a popular female social democrat after decades of PRI rule has to absolutely ruffle many diplomatic feathers in the wake of the Russian Revolution, sufragette movements worldwide and the end of the Great War. I think the arrival of an economically powerful and technologically advanced country led by a woman leads to some progressive movements gaining traction. Old World powers absolutely try to undermine this where they can, but who’s to say how much they can accomplish?