That definitely seems like the obvious origin. I'm surprised it isn't mentioned in the article.

For those who don't speak Swedish, the pun is in that "glass" is the Swedish word for ice cream.

edit: I can't resist pointing out that for the Swedish word "it" I'd rather say "det", hence referring to the action of eating ice cream rather than "den", referring to the ice cream itself.

Not sure if this is a joke or a mistake since the English "glass" is "glas" in Swedish, but the Swedish "glass" is "ice cream" in English. The correct translation in Swedish would be "Jag kan äta glas, det skadar inte mig".

I scream when I eat glass