Not only is this not really a great reason to duplicate a feature (unless you were to also remove the previous notation), it would be ambiguous because ? already has another meaning, for example:
foo() ? - bar() ? -1 : 2
could be equivalent to:
if foo() { -bar()? - 1 } else { 2 }
or
if foo()? - bar { -1 } else { 2 }