https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85282
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- Compare to e.g. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1825 which says "[Moved to DR at the November, 2016 meeting.]" That means it's a retroactive fix for previous standards. That isn't the case for 727.
