I haven't been suggesting using (A or B) as a name for (not ((not A) and (not B))) in constructive logic where they aren't equivalent. Rather, I have been suggesting using classical logic (where the above sentences are equivalent) with a constructivist interpretation, i.e. not making difference between "true" and "theorem". But since it is possible for (A or B) to be a theorem and simultaneously for both A and B to be non-theorems, logical "or" would not have the same interpretation, namely it wouldn't match the common language "or" (for when we say "A or B is true", we mean that indeed one of them must be true).