I was disappointed in Pope Francis' statement, too; but I think the headline that he had affirmed the finality of JPII's decision was misleading.  When asked if the decision of JPII was irrevocable, Francis said only that it seems that that's the way the issue is moving -- which i take to mean not much more than, "Well, I won't be the pope who changes it."  This change may or may not be initiated by a pope; it may arise from the local churches and spread through the church from the ground up.