Having lived overseas through 2 military coups (both bloodless), I can tell you that everything you are hearing from people in Brazil is entirely consistent with the way coups actually evolve. There are rumors, but no confirmed facts. Usually these rumors start a long time before the actual event. But people are still living their ordinary lives. Nothing appears to change.

Then suddenly, you wake up one morning, put on the coffee, rush around doing your morning routine preparing to go to work, and you get a call from your boss telling you the office is closed. Stupidly (because you woke up late and haven't looked at the news) you ask why, only to find out tanks have been rolled out during the middle of the night and martial law has been declared.

All those rumors, which everyone had started to discount because they had been going on so long, suddenly become real in an instant. Military operations are never announced. They merely happen. The fact that many people in Brazil are going about their daily lives and preparing for soccer matches does not mean the rumors about an impending coup are not real. If a coup is being arranged, this is exactly how you would expect it to look.