That's a good question Askander. But there are a number of points that should be reminded first:
The belief in primordial luminous (noori) existence of the Prophet is not a Shiite specific belief;
The belief that the Prophet is Allah's Light is mentioned in the Quran:
O People of the Book! Our Messenger has come to you, clarifying for
you much of what you kept hidden of the Book, and overlooking much. A
light from God has come to you, and a clear Book. (5:15)
Mani Sunni scholars have admitted that light in the above verse refers to the Holy Prophet. They include Suyuti, Tabari and Fakhr Razi. See this for references.
There are many traditions that that endorse this belief. For some examples and a relevant discussion look at this article.
Now to answer your question, you should note that prophet's worldly/bodily existence is different from his primordial luminous substance. The verse you quoted refers to Prophet's worldly existence. It is evident that the Holy Prophet was not born and physically present during the time of Prophet Moses. But the question rises, how could then he know about those past realities? The answer relies in the very theory of Prophet's Light. The fact that the Holy Prophet was enlightened about those realities is a testimony to the primordial existence of Prophet's Light through which he was informed about them, and in fact all realities of the universe.
Also note that "primordial" existence of Prophet's Light doesn't mean that it existed at the beginning of time but rather in a sphere above and beyond time in the closest possible level to Allah's essence.