I disagree, if the boxer is good and wins a medal he will get signed and start his career. Protesting on the medal stand or during a fight will give him some media attention, but his first few fights will be on undercards that are not televised until he puts together some wins in the 6-8 round bouts he will fight.
A boxer does not need to kneel at the medal ceremony to get paid. Also, two weeks after the Olympics the media will move on to something else and stop giving a shit like they always do.
If the boxer is good and wins a medal he will get signed and start his career. But if he kneels he will start his career with publicity and mainstream media attention that a beginning boxer could only dream of.That publicity makes people want to see him fight,whether they like him,hate him, or are just curious to see what the hype is about.