The "divine law" that Amoris fn. 351 supposedly gives "a nudge and wink to" is Canon 915, which excludes from Communion those "obstinately persevering in manifest grave sin."  That's the 'divine law' that excludes the remarried without a Decree of Nullity from Communion; Jesus and the Gospels do not pronounce themselves on the specific question (access to the Eucharist).  IMHO, the need for clarification is not urgent.  In fact, the matter appears to me to be of pastoral application, not dogma.  I do not state that as a strongly held view, but under the circumstances, I will follow the Pope and I think the challengers have the burden to show otherwise.