I doubt whether the majority of bishops questioned it. It was brought up by Cardinal Kasper so the bishops had to discuss it. The Pope should never have allowed it to be on the agenda especially as it had been reaffirmed by one of his recent predecessors.
Any Catholic who is divorced and remarried is deceiving himself if he thinks he is not committing adultery and thinks that adultery isn't a mortal sin. The 'settled' teaching going back to Apostolic times (1 Cor 11:27) is that one should not receive the Eucharist unworthily. The Church has consistently taught that this means not being in a state of grace or to put it another way in a state of mortal sin. Any Catholic who values his Faith would know this. If he doesn't then it is doubtful that he would even care whether he was in a state of sin or not.
My standard for determining settled doctrine is what has been consistently taught by popes and councils down the centuries.