I think they're getting too much attention to be honest. Anti-Northeastern xenophobia has always existed, though it has risen the last decade (I think Vladimir Safatle, of all people, got it right). São Paulo is the conservative bulwark, the state that elects the worst kind of murderers. We know that.
There were 2,500 thousand people in the biggest, most populated and reactionary city in the country. This doesn't mean anything, really. Any leftoid march will gather as much, and we're nowhere close to a revolution. Not to mention that the Military Club, prominent bankers (Bradesco, Itaú etc) greeted Dilma's reelection (of course market's favourite candidate was Aécio, though), even fucking Obama did so as well.
There will be no coup, because there's no need for one. And there's not much that Bolsonaro family, Raio Privatizador (Privatization Lightning, topkek) etc can do about it.
Keep an eye open, sure.
"We have seen: a social revolution possesses a total point of view because – even if it is confined to only one factory district – it represents a protest by man against a dehumanized life" - Marx
"But to push ahead to the victory of socialism we need a strong, activist, educated proletariat, and masses whose power lies in intellectual culture as well as numbers." - Luxemburg
fka the greatest Czech player of all time, aka Pavel Nedved