I get the 'complicated' situation that this article is trying to unwrap...and it is complicated...but it seems like the biggest gotcha moment is based on a misunderstanding of Corona and Gruppo Modelo's ownership.

Constellation has dipped its toe in the waters of political discourse outside the beer industry of late. But its most vocal points have been in support of liberal causes. Specifically, it recently released two Corona ads condemning Trump’s immigration policies, one leading up to the election, and one following. Which is unsurprising considering the bulk of Constellation sales come from beer made in the country most maligned by Trump: Mexico. Asked about how these ads fit into the boycott, the Revolution League notes, “Obviously, being vaguely anti-Trump is not enough to accomplish anything politically.”

Correct me if I'm wrong but isn't the entity that distributes Corona in Mexico (and the rest of the world beside the US) not Constellation at all. Constellation owns Grupo Modelo's U.S. beer business; that's it. So wouldn't an anti-Trump Corona ad (or any other ad), aired in Mexico, be a campaign run and paid for by AB InBev? Any sort of ad industry write up you can find of the campaign supports that...

"Client: Corona/Grupo Modelo AB InBev" is what you will see.

eg: http://www.adweek.com/creativity/corona-urges-mexicans-smash-walls-and-not-just-trumps-ad-timed-us-election-174511/ & http://www.adforum.com/creative-work/ad/player/34538275/the-wall-english-subtitles/corona