when Arthur broke into the theater dressed as the bell boy or such to confronted Thomas. There's a protest outside but the rich and the elite just don't give a damn
about it and enjoyed the Charlie Chaplin show instead.

this probably shown us that the riches/elites of Gotham just didn't give a damn or thinks too little about the lower society/people of Gotham, nor did they think they're(the people) gutsy enough to do
anything to them(the riches)....until that talk show with Joker & Murray..

..which spark something or violent tendencies to the rioters. Esp when Wayne's shooter uttered the same words like Joker did to Murray before blowing em up

it didnt start with a riot rite... only a demonstration n rally.. it started out into a riot after the cop accidentally killed one of the people in the train.. so it could possibly mean that the waynes was already in the movie theatre not thinking that a rally n demonstration could turn into a riot