Generally, I think people are going by Shen Wei's backstory of how recent the meteor strike was, and the privation he suffered before pretty much immediately becoming a child soldier, and drawing the logical conclusion that honey and sugar cane are in short supply in YOHE. Honey, at least, lasts a while, and some food storage may have survived the meteor strike, but I imagine any such supplies are saved for medicinal and preservation applications during wartime. I don't think it's impossible he's tasted something as sweet as the lollipop before. I just don't think it's likely.

That said, I agree that what surprises him in that scene is someone shoving something in his mouth, and probably the artificial flavor.