The suggestion that the quran is not necessarily describing a young earth is nice, but it hardly matters. It doesnt matter how many days, or billions of years allah took to create the universe. As long as Allah believes that there was a first human (and especially a first human with no parents), he will fail any exam on the topic of evolution.
the issue of evolution, for many people, hinges on whether one takes the story of Adam and Eve literally or not.
I am of the personal opinion that this story is not literal,
so he believes that the first prophet of islam did not exist.
He makes a distinction between metaphorical prophets and literal ones. He is welcome to do so, but he cannot claim that this is Islam.
In other words you can maintain beliefs in Islam and Evolution, as long as you don't really believe in Islam.
4:150 "And those who believe in God and His messengers and do not make a distinction between any of them - God will grant them their rewards; and God is Forgiving, Merciful"