In the early 19th Century, the Saudis were becoming ever more powerful from their base in central Arabia. If Napoleon never went to Egypt, Muhammad Ali would never come to power, and his dramatic military and social reforms never happen. That means there isn't a powerful European-style Egyptian army for the Arabian campaigns, which our timeline resulted in the crushing of Saudi power.
If this doesn't happen, what happens to the Saudis? Do they take over all of Arabia, including the Holy Cities? Would they be able to start moving into Iraq and Syria?