text: "Law is an ordinance of reason, promulgated by rightful authority for the common good."
  [Aquinas].  When the needs of the common good change, because of the times, because of historical changes, because the needs of human society REQUIRE a change---laws also must change.
  
  Each one of the catechisms that you mentioned were written at a certain time and place in history.   Those times and places are LONG past.  Even the CCC of 1983, failed to understand that instant worldwide communications and accelerated travel give rise to both complications and opportunities regarding the diversity of disciplinary practices.  Millions have almost immediate access to information about whatever practice occurs in any regional [diocesan] church.  Shared knowledge is a source of further creative adaptations, and is a force for freedom in local churches, rather than an excuse for NEEDLESS UNIFORMITY or HOMOGENIZATION.