Will be interested too to see what UA does in the very back with seating. Delta has a standard aft galley and lav arrangement on the neo but on the regular A321 has this space flex config (two lavs under the tail). They block 42ABC for crew use because there is nowhere really for the crew to sit inflight. One of the jumpseats is built into a lavatory door (or folds out over the galley carts like Spirit does) and the other faces the two lavatories. A lot of crews block the lav closest to the door so they can use that jumpseat.