The article by Ritzau discussed the difficulty encountered by the writer Kåre Bluitgen, who was initially unable to find an illustrator prepared to work with Bluitgen on his children's book

So there was NOT a textbook scrapped. No censorship. There was an author trying to employ an illustrator, and refusals to do this work.

The first one to decline the job was a Muslim, who refused on religious grounds (not menitoned in the Wikipedia article). Then there were refusals because people THOUGHT there could be violence from Muslims, but there weren't any real threats.

Only after the cartoon campaign of Jyllands Posten there were death threats and riots.