The company has a rule against wearing necklaces. No matter what the symbol. I don’t consider this an anti Christian ruling, based on the info in the article.
It said he is welcome to wear a christian symbol on a ring or earring. Headscarves are allowed as long as they have the company symbol.
And how is that different from around his necK?
He’s not likely to wear an earring and wearing a ring as a symbol is not typical among Christians, particularly among ME Catholics or Orthodox (I assume he’s a Copt). In fact, I doubt that even Dutch Christians normally wear a cross earring or a ring. This type of religious jewelry is something you see pretty much only among a certain segment of American Protestants, so I’d say he’s not likely to have a cross earring or ring in his sock drawer.
In other words, this law was made to prevent the wearing of Christian symbols, and the law needs to be challenged. I doubt that Jews are forbidden from wearing a yarmulke (although with the heavy Muslim population, apparently many of them have stopped wearing them) and obviously Muslims are not stopped from making their women shroud themselves like ghouls, so there’s only one group that suffers from this.