If elves are the children of disorder and even their creative side is born of chaos one wonders about their history. One unique aspect of elves in Tolkien (and many of his imitators) is that they alone can breed with humans. This suggests some common heritage in the later works (The Similrillon covers the bases for Tolkien).
In The World After elves are the children of creative chaos, specifically the children of Lilith and Adam while humans are the children of Eve and Adam. Their disappearance from this world came with the casting out of Lilith in favor of Eve and their return stems from her ability to return when the order of the world was broken by The Harrowing.
Because they are children of disorder and chaos they have no connection to the power of order and thus are restricted from clerical magic. However, their direct decent from creative chaos give them inherent magical abilities. At the same time that connection skews their magic towards the creative side and thus presents them more limited destructive abilities than human mages while giving them slightly more creative options.