An 'antiproviso problem' for appositive relative clauses

The semantic content contributed by appositive relative clauses is expected to
“project”, i.e. entail commitments for the actual speaker independently of the syntactic environment the appositive occurs in (see e.g. Potts 2005, Koev 2013). In (1), the unaltered appositive content (that Edward is from Minnesota) is attributed to the speaker even though the appositive itself is presumably in the syntactic scope of a possibility modal.