I don't think the bathroom thing is as big a deal as people make it out to be. Single aisle is slightly annoying to get around people but the ratio of pax to lavs isn't anything crazy.
321NEO:
1 bathroom for 20J pax = 20:1
3 bathrooms for 176 Y pax = 35:1
XLR:
1 bathroom for 20 J pax = 20:1
3 bathrooms for 135 PE + Y pax = 45:1
787-9P
3 bathrooms for 51 pax = 17:1 in BC
3 bathrooms for 193 PE + Y pax = 64:1
Please check your math on the NEO Y