Mr McGain, who was filmed interviewing the boy on the Gold Coast during Schoolies celebrations, was seen laughing when the teen said: "I'm fed up with having all these sports stars stand out on our stages and not sing the national anthem.
"I mean we've got to stop celebrating a culture that couldn't even invent the bloody wheel for God's sake. We've got to start enjoying and living in Western culture."
Mr McGain told AAP on Tuesday "the powers that be" had banned him from commenting about the incident.
"It has been a whirlwind 24 hours but hopefully I can go back to being a normal 19-year-old. I just have to let it go and move on," he said.
Another video emerged on Tuesday of Mr McGain impersonating Donald Trump at the Great Wall of China.
The video, posted on youtube last year, shows Mr McGain saying "this is not the greatest wall but it's a great wall ... We're going to build the greatest wall, it is going to be to keep out the Mexicans, not the Mongolians, or the chikedy chongs, not Genghis Khan bing bong, bing bong."
The party's leader, Deb Frecklington, has so far refused to be drawn on the issue.
However senior members of the Queensland Labor government say she needs to apologise.
"There is zero excuse and Deb Frecklington needs to apologise," Premier Annastacia Palaszczuk said in a statement on Wednesday.
"She needs to stand up today and do what she failed to do yesterday," State Labor's indigenous Environment Minister Leeanne Enoch added.