Quote from article: "Allah is an Arabic word that means “God” or, more accurately, “the God.”
Here is a Quranic passage that include both words so it will be easy to recognize their differences.
هُوَ اللَّهُ الَّذِي لَا إِلَهَ إِلَّا هُوَ
He is Allah, than whom there is no other God
اللَّهُ
إِلَهَ
The first word is Allah which is the name of God in Islam. The second word is ilah which means god in Arabic. They are not the same. One is a proper name while the other is a common noun. Therefore the article was being deceitful in stating that the two words are the same.
Additionally, nothing strange if Arab Christians refer to God as Allah as that name is more common to describe God no different from Muslims in western countries referring to Allah as God. Oh, by the way, the word Alah is also mentioned in the Old Testament.