Maybe genies can't mess with the timeline.If Aladdin had been smart and said “Genie, I wish I had been born as a prince,” there wouldn't have been a problem - the Genie would have completely changed who he was, not just slapped some fancy clothes on him.
At least he didn't squander his first wish by wishing for some sausages.The problem was that Aladdin screwed up his first wish by wishing for Genie to make him a prince.