Ariana Grande Responds to Threats Over Missing 'Wicked: For Good' Premiere

11/5 2:46 PM PT -- A fellow passenger, Connor Gowland, tells TMZ ... he was seated near Ariana and says she was already on the plane and fully expecting to make the São Paulo premiere before the travel chaos hit.

Grande went incognito in a baseball cap, face mask and cozy slippers, sitting in business class with her team of six when the chaos hit. Instead of stressing about her own schedule, Ariana actually comforted Connor about potentially missing his cousin’s wedding.

Ariana Grande’s firing back at some seriously wicked hate ... pleading with fans to stop sending cruel threats toward her and her team after a flight mishap caused them to miss the "Wicked: For Good" premiere in Brazil.

In an IG post Tuesday, Ariana sounded shaken as she addressed the backlash ... apologizing profusely for missing the premiere, and imploring people to stop wishing danger on her and her team.

Ariana laid it all out ... saying there was literally nothing she or her team could’ve done to make it to Brazil in time -- adding she was more disappointed than anyone else.

Clearly, Ariana didn’t see the backlash coming after she first posted that her team had to deplane en route to Brazil over safety concerns.