While is may be desirable to change the will of children, as in bending their natural choice of words, in some instances I firmly believe that whoever wrote the above linked document has no idea whatsoever on how children interact.
Children and plain speakers, as such it should be obvious to any person who has had children that sometimes their choice of words may be offensive to adult ears. This does not make the words uttered wrong. It does not mean that the child or indeed the childs parents, are racist in any way but shows that the chid is expanding their vocabulary.
Should we beat on the will of children? No.
Should we endeavor to get children to speak with the iron grip of adult speak? No.
Quite simply that document shows everything that is wrong with this country.