I'm gonna reply to the original OP. In background, I'm a WP who usually travels in Y, but occasionally upgrades to J domestic. I'm assuming this is about 737s, because 767s have a twin aisle & therefore different layout for WCs. I can't believe the fuss. The aircraft map suggests 3 toilets, it doesn't specify J or Y. With one aisle, it is usually impossible for someone in the first few rows of Y to get back to the 'Y' toilets during any service, which at times can be debilitating, due to the J lounge :mrgreen:
When I've been in Y, I've only ever gone forward if there's no one in the 'office', and it's difficult to go aft. As for business, I've never had an issue with people coming forward. Most of my seat bumps are staff, not Y pax coming forward. Seriously, in a 737, it's a toilet!, not a right. There's 12 pax (max) forward for 1 toilet, & 100+ aft with 2 toilets (& 1 aisle). If the need arises, and the aisle is blocked, I'm gonna go forward.