Unexpectedly predicts what's written down (8)

I believe the answer is:

scripted

'written down' is the definition.
(written in a script)

'unexpectedly predicts' is the wordplay.
'unexpectedly' indicates an anagram.
'predicts' with letters rearranged gives 'SCRIPTED'.

'what's' acts as a link.

I've seen this clue in The Guardian.

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