This is the opening sentence from the Edgar Allan Poe short story 'The Facts In The Case Of M. Valdemar'.
Of course I shall not pretend to consider it any matter for wonder that the extraordinary case of M. Valdemar has excited discussion.
It seems to me that 'it' in this sentence is not a dummy 'it' but a pronoun that refers forward to the subordinate clause 'that the extraordinary case of M. Valdemar has excited discussion.' We could rewrite the sentence as 'Of course I shall not pretend to consider that the extraordinary case of M. Valdemar has excited discussion any matter for wonder .' The problem would be that 'consider that' is a common construction that utilises 'that' in a different way than is intended here (as introduction to a subordinate clause), so instead the pronoun 'it' is used to separate off the clause.
On the other hand, we could write 'That the extraordinary case of M. Valdemar has excited discussion, I shall, of course, not pretend to consider any matter for wonder.'
Does my analysis make sense, and are there many instances where a pronoun refers forward to something that occurs later in a sentence?
For instance--"I consider him damned, who refuses to submit to God" where there is no previous noun the pronoun 'him' refers to, but 'him' instead refers to the following subordinate clause 'who refuses to submit to God'. (Which raises the interesting case of a subordinate clause that modifies a pronoun that actually refers to the subordinate clause--but then, 'he who refuses to submit to God' would work the same way.)