Sanchez was dropped for their last league game v West Ham.No he's not been relegated to cup keeper - they've played 4 PL games this year and he's been the keeper for all of them. The only game he's not been their keeper for was in the cup against Morecombe.
He's not been dropped despite being despised and making a lot of errors. Bart is young and has potential still, so dropping him for a few errors would be a mistake.