No it doesn't at all. The Muslims themselves in Saudi Arabia are more credible than "historian" . I never heard that before. The Koran wasn't changed. The mainstream one isn't changed. We all have the same views on most things. Christian texts, modern ones say different things in regards to specific events such as Genesis 1 or Genesis 2, they have differences some people will say is a significant difference
It seems you need some lessons in history so you can come to an understanding of the false assumptions you have.
Let's understand that the lineage of the Koran is irreparably broken in three places. Those places are:
1. The 'Uthmanic'' rescension.
2. The Compilation under Abu Bakr.
3. The chain of transmittal prior to Muhammad.
For those of us who have made an effort to understand the compilation and standardization on the mushaf of 'Uthman, such self reference is more prosaically explained by the late date of this version.
The fact remains that "Qur'an" means "recitation," not book. It did not become a book until years after Muhammad's death.
Without going into too much detail, rather than "numerous" sahabahs with perfect recollections of the Koran, there is compelling evidence that these earliest sahabahs had different and differentially complete memories. How else is one to make sense of the ahadith (repeated in one form or another at least seven times) concerning the last verse being found in the memory of only a single man; Abi Khuzaima Al-Ansari? Doesn't that require the understanding that every other sahabah had an incomplete memory?
How does one further account for the conflicts among those sahabahs that required the Uthmanic rescension?
In fact, how does one account for Uthman's rescension at all?
It is pretty clear that the "perfect preservation" of the Koran did not commence until after the rescension. And even then, we could get into a wonderful discussion of the multiple readings, but why bother. The point is made. Second, giving the fact we have a historical record of the event during which the Koran was standardized and competing versions burned, the maintenance of a standard since that time hardly qualifies as suggesting that Mohammed would have even recognized the writings. The completely human engine for that standard is evident and obvious. We have in our possession, at best, the musshaf of Uthman. We really do not know what the musshaf of Muhammad contained, and how different the two might be.