A two-year-old comment on an internet discussion board is hardly ironclad proof. It is an opinion or interpretation written by an anonymous or semi-anonymous poster.
Surprisingly, I am not qualified to comment on the intricacies of Syriac lexical morphology. Suffice it to say that if the internet comment you cite is accurate, it is clear that "Lord Yah" is not the same as "I am that I am". It is a title (denoted by "Mar") and not the statement that God made on Sinai.
Islam has nothing remotely similar to this.
Apparently, only the Syriac scriptures do. Are all other Christian denominations heretical?
More here :
http://cachicas.7host.com/shmaisrael/english/aramaic.htm
Maryah/(Mariah) Aramic/(Syriac) = Yahweh