Airplane bathrooms Get Smaller to Squeze in More Seats - The Middle Seat Terminal - WSJ
As a matter of policy, I do not visit the lav on flights 3 hours or less. I would hold it in before I risk being wedged inside one of them permanently.
But, hey, 4 more seats in Coach. That's enough to bring tears to eyes of them bean counters.
Anyway, I much prefer the Japanese style toilets of basically a hole in the ground. I can squat real good and prefer that to sitting.